Subscribe Now Subscribe Today
Research Article
 

Tropical Soil Fungi Producing Cellulase and Related Enzymes in Biodegradation



Pradub Reanprayoon and Wattanachai Pathomsiriwong
 
Facebook Twitter Digg Reddit Linkedin StumbleUpon E-mail
ABSTRACT

The objective of this study was to screen, identify and characterize of cellulolytic fungi from various soil management fields; organic, young organic, semi-chemical and chemical soil from Surin rice fields, Thailand. Fungi from various type of soils were isolated by dilution plating technique on Reese minimal medium supplemented with cellulose powder and rice straw then incubated at 25°C for 3-7 days. The isolated fungi were screened and identified using slide culture technique. The enzymatic activities were assessed by qualitative method for cellulase, xylanase, peroxidase and laccase activities. Two-hundred and fifty-eight fungi isolates found in Surin rice fields belonging to the genus Penicillium (5 species), Paecilomyces (4 species), Aspergillus (3 species), Acremonium (2 species), Chaetomium (2 species), Alternaria (1 species), Bipolaris (1 species), Curvularia (1 species), Fusarium (1 species), Humicola (1 species), Mucor (1 species), Nigrospora (1 species), Phoma (1 species), Pyrenochaeta (1 species), Pythium (1 species), Rhizopus (1 species), Sporotrichum (1 species) and Trichoderma (1 species). Out of 29 fungal species clearly showed different in enzymatic activities. Most tropical soil fungi had ability to produce cellulase, xylanase, laccase and peroxidase, respectively. The highest capacity was found only in cellulase. Aspergillus niger, Aspergillus sp., Chaetomium murorum and Trichoderma sp. showed the highest potential to produce cellulase. Eleven species of soil fungi showed high capacity in xylanase activity. For laccase and peroxidase activity, there were found in 2 species. The results also revealed that only ten showed highest carboxymethyl cellulase, xylanase, peroxidase and laccase activities by qualitative screening method for enzymatic assay. They were identified as Aspergillus niger, Acremonium sp., Aspergillus sp., Chaetomium murorum, Humicola grisea, Mucor sp., Paecilomyces victoriae, Penicillium janthinellum, Penicillium lanosum and Trichoderma sp. These tropical soil fungi will be beneficial to use for biodegradation and decomposition of agricultural residues, especially rice straw.

Services
Related Articles in ASCI
Similar Articles in this Journal
Search in Google Scholar
View Citation
Report Citation

 
  How to cite this article:

Pradub Reanprayoon and Wattanachai Pathomsiriwong, 2012. Tropical Soil Fungi Producing Cellulase and Related Enzymes in Biodegradation. Journal of Applied Sciences, 12: 1909-1916.

DOI: 10.3923/jas.2012.1909.1916

URL: https://scialert.net/abstract/?doi=jas.2012.1909.1916
 
Received: April 02, 2012; Accepted: July 23, 2012; Published: September 08, 2012



INTRODUCTION

The expansion of rice cultivation has led to produce large amount of rice straw (Gadde et al., 2009b). About 50% of the dry weight of the rice plant makes up straw waste (Abdulla and El-Shatoury, 2007; Kausar et al., 2010) and each year the straw from rice farming has increased and accumulated every year. Because major components of rice straw are cellulose and hemicellulose encrusted by lignin and only small amounts of protein, it is resistant to microbial decomposition compared to straw from other protein-rich grains such as wheat and barely (Parr et al., 1992). In addition, rice straw is considered as disease infestation, unstable nutrients and slow rate in degradation. Therefore, the post-harvest rice residue normally is eliminated by open-field burning in several countries such as Philippines, Thailand and India (Gadde et al., 2009a, b; Kausar et al., 2010). Currently, effects of paddy straw burning in the fields are coming serious concern all over the world because this process emits many pollutants. For example, carbon dioxide, carbon monoxide, methane, nitrous oxide, sulphur dioxide, polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxins (PCDs) etc. (Gadde et al., 2009a; Kausar et al., 2010). These pollutants represent a threat to public health and pose an environmental pollution problem. Especially, polycyclic aromatic hydrocarbons (PAHs), PCDFs and PCDs, several scientific researches have been reported that these pollutants are carcinogenic substances which can be cause severe impacts on human health. Emissions from field burning activities also release many respiratory particles of <10 μm size (PM10, particulate matter less than 10 μm in diameter) which deteriorate local air quality and cause high personal exposure (Belal and El-Mahrouk, 2010; Oanh et al., 2011). Thailand about 48% of rice residues is burned in the field (Gadde et al., 2009b; Kausar et al., 2010; Oanh et al., 2011). Thailand produced massive amounts of rice straw more than other countries because availability in rice cultivation over 3-4 times a year. Also together with many patterns of rice cultivations by direct dry seeding, wet seeding and indirect seeding under organic, young organic, semi-chemical and chemical management practices and there are in wet and dry seasons. Therefore, rice straw residues are varieties in moisture and temperature conditions. It continuously accumulated year round. Although, rice straw composes of three major components, the chemical compositions of tissue part as total ash, insoluble ash (silicon), cellulose, hemicellulose and lignin contents varied greatly among the different area (Jin and Chen, 2007; Rodriguez et al., 2009). The biodegradation of rice straw are related with soil microorganisms (Kuhad et al., 1997; Yu et al., 2007) as Actinomycetes (Abdulla and El-Shatoury, 2007; Minamiyama et al., 2003; Xu and Yang, 2010) bacteria (Xu et al., 2005) and fungi (Chandra et al., 2007; Hart et al., 2002; Kumar et al., 2008; Stepanova et al., 2003). Many researches have been reported that fungi showed the most efficiency for biodegradation processes (De Castro et al., 2010; Liang et al., 2010). However, this process takes longer time to apply and need optimal environments. The soil fungi isolated from the agricultural soil is able to produce cellulolytic enzymes for degradation process and make rice straw degradation more feasibility. The soil fungi from direct agricultural area can reduce the problems of time consuming and environmental factors for biodegradation process and also reducing the cost for soil improvement. In addition, it also reduced air and soil pollutions that affect human health from open air burning. The screening of soil fungi producing cellulases and related enzymes in biodegradation is important for Thailand. The objective of this research is to isolate and screen tropical soil fungi for lignocellulose degrading enzyme productions from various paddy soils. It is hoped that this will be a step towards providing a method of accelerated decomposition of rice straw in paddy fields.

MATERIALS AND METHODS

Isolation and identification of soil fungi: About 1 g of soils from various Surin rice fields in Thailand, as organic, young organic, semi-chemical and chemical management practices were collected between August 2010-December 2011. The soil samples were suspended into sterile distilled water and aliquots of the resulting suspension were inoculated onto Reese minimal medium by dilution plating technique (Kumar et al., 2008; Yang et al., 2003). After 7-14 days of incubation at 30°C, several different colonies were purified and then characterized by morphological characteristics. Based on the methods of colony observation with a stereoscope and microscopic features of fungal strains with a light microscope; squash mounts stained with Lactophenol and Cotton blue, used to identify fungal cultures to species level (Alves-Prado et al., 2010; Barnett and Hunter, 1999; Watanabe, 2002).

Inoculation procedure: Pure cultures were cultivated on basal medium (LMB) containing: KH2PO4 (1 g L-1), ammonium tartrate (0.5 g L-1), MgSO4.7H2O (0.01 g L-1), CaCl2.2H2O (0.01 g L-1), yeast extract (0.001 g L-1), CuSO4.5H2O (0.001 g L-1), Fe(SO4)3 (0.001 g L-1) and MnSO4 (0.001 g L-1). LBM medium was supplemented 0.4% w/v glucose and solidified with 1.60% w/v agar (Difco). All enzymatic assays were inoculated with agar disc (6 mm in diameter) of active mycelia from 5 day-old cultures on LBM medium cultivated in Petri dishes and incubated under the dark at 25°C (Tortella et al., 2008).

Qualitative enzymatic assay: The soil fungi were screened qualitatively for the production of degrading enzymes; cellulase, xylanase, laccase and lignin peroxidase. The media used for detecting the enzyme were prepared as follows (Minamiyama et al., 2003; Pointing, 1999; Tortella et al., 2008; Xu and Yang, 2010).

Cellulase activity: The Cellulolysis Basal Medium (CBM) was prepared containing: KH2PO4 (0.5 g L-1), ammonium tartrate (0.5 g L-1), MgSO4.7H2O (0.1 g L-1), CaCl2.2H2O (0.01 g L-1), yeast extract (0.001 g L-1), CuSO4.5H2O (0.001 g L-1), Fe(SO4)3 (0.001 g L-1) and MnSO4 (0.001 g L-1). LBM medium was supplemented with carboxymethyl cellulose 2% w/v (Sigma) and 1.6% of agar (Difco) and was autoclaved at 121°C for 20 min the medium was aseptically transferred to petri dishes and inoculated with a 6 mm agar disc cut from a 5 day old fungal culture of each strain separately and incubated at 25°C in darkness and, when the colony diameter was approximately 30 mm, were flooded with aqueous Congo red (2% w/v) for 15 min. Then, the agar surface was washed with distilled water and plates were flooded with NaCl (1 M) for 1.5 min. Production of cellulase was observed by the formation of a yellow-opaque area around the colonies.

Xylanase activity: The Xylanolysis Basal Medium (XBM) was prepared containing: ammonium tartrate (5 g L-1), KH2PO4 (1 g L-1), MgSO4.7H2O (0.5 g L-1), yeast extract (0.1 g L-1), CaCl2.2H2O (0.001 g L-1). The XBM medium was supplemented with xylan, 4% w/v (Sigma) and 1.6% w/v of agar (Difco) and autoclaved at 121°C for 20 min. The medium was aseptically transferred to petri dishes and inoculated with an 6 mm agar disc of isolated soil fungi. The petri dishes were incubated in the dark at 25°C and, when the colony diameter was approximately 30 mm, were flooded with iodine dye (0.25% w/v aqueous I2 and KI) for 5 min. Then, the agar surface was rinsed with distilled water. Production of xylanase enzyme was observed by the formation of a yellow-opaque area around the colonies compared to a blue/reddish purple color standard for non-degraded xylan.

Laccase activity: Laccase activity was determined in all isolated strains via the reaction with ABTS in basal medium (LBM) as the previous mentioned media. The basal medium was supplemented with 1 g L-1 of 2,2ยด-azino-bis 3-ethylbenzothiazoline-6-sulphonic acid (ABTS) and 16 g L-1 of agar (Difco). The medium was autoclaved at 121°C for 20 min. One milliliter of a separately sterilized 20% w/v aqueous glucose solution was added aseptically to each 100 mL of growth medium. The medium was subsequently aseptically transferred to petri dishes and inoculated with an 6 mm agar disc of fungal culture. Production of laccase was observed by the formation of a green color in the growth medium.

Peroxidase activity: Azure B agar was used for the production of lignin peroxidase. The LMB medium supplemented with 0.01% w/v of Azure B and 1.6% w/v agar (Difco). The medium was autoclaved at 121°C for 20 min. One milliliter of a separately sterilized 20% w/v aqueous glucose solution was added aseptically to each 100 mL of growth medium. The medium was subsequently aseptically transferred to petri dishes and inoculated with an 6 mm agar disc of fungal culture. The clearance of blue cloured medium is positive reaction of lignin peroxidase.

Hydrolysis capacity (HC value): HC was used to evaluate the capacity of degrading enzymes of soil fungi by diameter of the clearing zone/diameter of the colony (Xu and Yang, 2010).

RESULTS

Two-hundred and fifty-eight fungi isolates found in Surin rice fields belonging to the genus Penicillium (5 species), Paecilomyces (4 species), Aspergillus (3 species), Acremonium (2 species), Chaetomium (2 species), Alternaria (1 species), Bipolaris (1 species), Curvularia (1 species), Fusarium (1 species), Humicola (1 species), Mucor (1 species), Nigrospora (1 species), Phoma (1 species), Pyrenochaeta (1 species), Pythium (1 species), Rhizopus (1 species), Sporotrichum (1 species) and Trichoderma (1 species). Qualitative screening of the fungal cultures indicated that 29 strains showed various levels in cellulase, xylanase, peroxidase and laccase (Table 1).

Table 1: Qualitative enzyme production of soil fungi on solid plates of cellulase, xylanase, laccase, and peroxidase
HC value: Hydrolysis capacity, diameter of the clearing zone/diameter of the colony divided in 4 levels as *<1.00,**1.01-2.00, ***2.01-3.00 and ****>3.00

Fig. 1(a-b): Qualitative assays of cellulase and laccase activity, (a) CMC agar and (b) ABTS agar

The most of strains presented in cellulase (CMCase) activity followed xylanase, laccase and peroxidase, respectively. Four species of soil fungi that showed highest CMCase activity (>3.00 HC) were identified as Aspergillus niger, Aspergillus sp., Chaetomium murorum and Trichoderma sp. Whereas 12 species at high level (2.01-3.00 HC) were Acremonium alternatum, Acremonium sp., Aspergillus brevipes, Humicola grisea, Mucor sp., Nigrospora sp., Paecilomyces victoriae, Penicillium janthinellum, Penicillium lanosum, Penicillium nigricans, Penicillium sp. and Rhizopus sp. While 11 soil fungi showed high level of xylanase activity (2.01-3.00 HC) were Acremonium sp., Aspergillus niger, Aspergillus sp., Chaetomium murorum, Humicola grisea, Paecilomyces inflatus, Paecilomyces roseolus, Paecilomyces victoriae, Penicillium janthinellum, Penicillium lanosum and Trichoderma sp. The high level of laccase and peroxidase activities was obtained only two species. Humicola grisea and Paecilomyces inflates were laccase producers. Paecilomyces victoriae and Trichoderma sp. were peroxidase (Table 1, Fig. 1).

In addition, the results also clearly found that out of 29 soil fungal species, the ten most efficient capacity for CMCase, xylanase, laccase and peroxidase activity (HC >2.00 at least 2 activities) was identified as Acremonium sp., Aspergillus niger, Aspergillus sp., Chaetomium murorum, Humicola grisea, Mucor sp., Paecilomyces victoriae, Penicillium janthinellum, Penicillium lanosum and Trichoderma sp. according to Fig. 2.

DISCUSSION

This research indicated that many fungi strains isolated from agricultural soil in Surin province showed high efficiency of enzyme activity for biodegradation, especially, the genera of Trichoderma and Aspergillus. They also showed higher in enzymatic activities than other areas compared with other reported studies. Trichoderma from agriculture soil was HC value of cellulase and laccase >3.00 while Trichoderma from other areas was ranged between 2.00-2.50 (Gochev and Krastanov, 2007), 2.00-2.50 for cellulase and 1.61-2.22 for laccase (Toyama and Toyama, 2001). In addition, Xu et al. (2006) pointed out that the genera Aspergillus showed the diameter of the clearing zone/diameter of the colony between 1.30-1.90 for laccase activity. Dhouib et al. (2005) reported that Trichoderma species were only 1.00-1.25 of the diameter of the clearing zone/diameter of the colony for laccase activity. These variations may be the affects of agricultural management practices on paddy soils such as fertility amendment, water content, cropping system, plant cover, residue composition, straw burning and environmental factors (Bastias et al., 2009; Braun et al., 2010; Grishkan et al., 2008; Meriles et al., 2009; Wang et al., 2010; Whitelaw-Weckert et al., 2007). Bulluck et al. (2002) found that organic and synthetic fertility amendments significantly influenced soil microorganisms on organic and conventional farms. Especially, beneficial soil fungi in the genus Trichoderma, the numbers of Trichoderma species were higher in soils from fields with a history of organic than conventional production.

Fig. 2(a-j): Morphology of soil fungi isolated from various paddy soils having lignocellulose degrading enzymes, (a)Acremonium sp., (b) Aspergillus niger, (c) Aspergillus sp., (d) Chaetomium murorum, (e) Humicola grisea, (f) Mucor sp., (g) Paecilomyces victoriae (h) Penicillium janthinellum, (i) Penicillium lanosum and (j) Trichoderma sp.

The densities were also increased over time in fields with a conventional history but were remained lower over time in soils from organic compared to conventional fields. Soils with alternative amendments had also higher population densities of Trichoderma sp. than soils amended with synthetic fertilizers in vegetable. The occurrence and distribution of culturable soil fungi were significant differences in species distribution patterns with respect to soil pH, moisture, carbon, chlorophyll a, salinity, elevation and solar inputs (Connell et al., 2006). Arenz and Blanchette (2011) found that most soil fungi positively correlated with percent carbon and nitrogen while soil pH and conductivity were negatively correlated. In addition, Surin rice field located in northeast of Thailand. It has a tropical climate, with the annual temperature at 32°C and humidity averaged at 65% which is optimal condition for the growth of microorganisms (Reanprayoon and Yoonaiwong, 2012). These directly result to soil fungi population densities and biodegradation of rice straw. This research also found that the genera Trichoderma and Aspergillus are dominant genera in tropical soils in agreement with many studies. Qiao et al. (2008) indicated that fungi belong to the important components in soil microbial biomass of forests. Aspergillus and Acremonium were the most dominant of fungi isolated from forest soils (Cabello and Arambarri, 2002; Qiao et al., 2008). For agricultural soils, Aspergillus and Trichoderma were the prevalent genera (Donner et al., 2009; Jaime-Garcia and Cotty, 2010; Kausar et al., 2010; Liu et al., 2008; Porras et al., 2007; Shukla et al., 2012). For biodegradability of soil fungi, many reports also indicated that Penicillium, Paecilomyces and Aspergillus were effective in degrading plastics (Bansal et al., 2012; Kausar et al., 2010; Kim et al., 2000). These isolated fungi could be used for biodegradations of natural and synthetic materials in soil effectively.

CONCLUSION

Twenty nine strains of soil fungi were isolated from various agricultural soils as organic, young organic, semi-chemical and chemical soil from Surin rice fields, Thailand. Only ten strains found high activity in lignocellulolytic enzyme productions. Most tropical soil fungi showed ability to produce cellulase, xylanase, laccase and peroxidase, respectively. Aspergillus niger, Aspergillus sp., Chaetomium murorum and Trichoderma sp. showed the highest potential to produce cellulase. Acremonium sp., Aspergillus niger, Aspergillus sp., Chaetomium murorum, Humicola grisea, Paecilomyces inflatus, Paecilomyces roseolus, Paecilomyces victoriae, Penicillium janthinellum, Penicillium lanosum and Trichoderma sp. found in xylanase activity. For peroxidase, Paecilomyces victoriae and Trichoderma sp. were peroxidase producers while Humicola grisea and Paecilomyces inflates were laccase producers. The result also revealed that ten species showed highest carboxymethyl cellulase, xylanase, peroxidase and laccase activities by qualitative screening method for enzymatic assay. They were identified as Aspergillus niger, Acremonium sp., Aspergillus sp., Chaetomium murorum, Humicola grisea, Mucor sp., Paecilomyces victoriae, Penicillium janthinellum, Penicillium lanosum, Trichoderma sp. These tropical soil fungi will be a step towards providing a method of accelerated decomposition of agricultural residues and for biodegradation process.

ACKNOWLEDGMENTS

The authors wish to thank Thailand Research Fund and the Commission of Higher Education for financial support under the project MRG 50800047 and The Office of the National Research Council of Thailand for partial support. We also express our gratitude to Associate Prof. Sayam Arunsrimorakot, Mahidol University for constructive comments and discussions and Faculty of Science and Technology, Surindra Rajabhat University for facilities in laboratory.

REFERENCES
Abdulla, H.M. and S. El-Shatoury, 2007. Actinomycetes in rice straw decomposition. Waste Manage., 27: 850-853.
Direct Link  |  

Alves-Prado ,H.F., F.C.Pavezzi, R.S.R. Leite, V.M. De Oliveira, L.D. Sette and R. Dasilva, 2010. Screening and production study of microbial xylanase producers from Brazilian cerrado. Applied Biochem. Biotechnol., 161: 333-346.
CrossRef  |  PubMed  |  

Arenz, B.E. and R.A. Blanchette, 2011. Distribution and abundance of soil fungi in Antarctica at sites on the Peninsula, Ross sea region and McMurdo dry Valleys. Soil Biol. Biochem., 43: 308-315.
CrossRef  |  

Bansal, N., R. Tewari, R. Soni and S.K. Soni, 2012. Production of cellulases from Aspergillus niger NS-2 in solid state fermentation on agricultural and kitchen waste residues. Waste Manage., 10.1016/j.wasman.2012.03.006

Barnett, H.L. and B.B. Hunter, 1999. Illustrated Genera of Imperfecti Fungi. 4th Edn., The American Phytopathological Society, St Paul, MN, USA.

Bastias, B.A., I.C. Anderson, J.I. Rangel-Castro, P.I. Parkin, J.I. Prosser and J.W.G. Cairney, 2009. Influence of repeated prescribed burning on incorporation of 13C from cellulose by forest soil fungi as determined by RNA stable isotope probing. Soil Biol. Biochem., 41: 467-472.
CrossRef  |  

Belal, E.B. and M.E. El-Mahrouk, 2010. Solid-state fermentation of rice straw residues for its use as growing medium in ornamental nurseries. Acta Astronaut., 67: 1081-1089.
CrossRef  |  

Braun, B., U. Bockelmann, E. Grohmann and U. Szewzyk, 2010. Bacterial soil communities affected by water-repellency. Geoderma, 158: 343-351.
CrossRef  |  

Bulluck, L.R., M. Brosius, G.K. Evanylo and J.B. Ristaino, 2002. Organic and synthetic fertility amendments influence soil microbial, physical and chemical properties on organic and conventional farms. Applied Soil Ecol., 19: 147-160.
CrossRef  |  Direct Link  |  

Cabello, M. and A. Arambarri, 2002. Diversity in soil fungi from undisturbed and disturbed Celtis tala and Scutia buxifolia forests in the Eastern Buenos Aires province (Argentina). Microbiol. Res., 157: 115-125.
CrossRef  |  

Chandra, M.S., B. Viswanath and B.R. Reddy, 2007. Cellulolytic enzymes on lignocellulosic substrates in solid state fermentation by Aspergillus niger. Indian J. Microbiol., 47: 323-328.
CrossRef  |  Direct Link  |  

Connell, L., R. Redman, S. Craig and R. Rodriguez, 2006. Distribution and abundance of fungi in the soils of Taylor Valley, Antarctica. Soil Biol. Biochem., 38: 3083-3094.
CrossRef  |  

De Castro, A.M., T.V. De Andrea, L.R. Castilho and D.M.G. Freire, 2010. Use of mesophilic fungal amylases produced by solid-state fermentation in the cold hydrolysis of raw babassu cake starch. Applied Biochem. Biotechnol., 162: 1612-1625.
CrossRef  |  PubMed  |  

Dhouib, A., M. Hamza, H. Zouari, T. Mechichi and R. Hmidi et al., 2005. Screening for ligninolytic enzyme production by diverse fungi from Tunisia. World J. Microbiol. Biotechnol., 21: 1415-1423.
CrossRef  |  Direct Link  |  

Donner, M., J. Atehnkeng, R.A. Sikora, R. Bandyopadhyay and P.J. Cotty, 2009. Distribution of Aspergillus section Flavi in soils of maize fields in three agroecological zones of Nigeria. Soil Biol. Biochem., 41: 37-44.
CrossRef  |  

Gadde, B., C. Menke and R. Wassmann, 2009. Rice straw as a renewable energy source in India, Thailand and the Philippines: Overall potential and limitations for energy contribution and greenhouse gas mitigation. Biomass Bioenergy, 33: 1532-1546.
CrossRef  |  Direct Link  |  

Gadde, B., S. Bonnet, C. Menke and S. Garivait, 2009. Air pollutant emissions from rice straw open field burning in India, Thailand and the Philippines. Environ. Pollu., 157: 1554-1558.
CrossRef  |  Direct Link  |  

Gochev, V.K. and A.I. Krastanov, 2007. Isolation of laccase producing Trichoderma Spp. Bulgarina J. Agric. Sci., 13: 171-176.
Direct Link  |  

Grishkan, I., A. Tsatskin and E. Nevo, 2008. Diversity of cultured microfungal communities in surface horizons of soils on different lithologies in Upper Galilee, Israel. Eur. J. Soil Biol., 44: 180-190.
CrossRef  |  

Hart, T.D., F.A.A.M. De Leij, G. Kinsey, J. Kelley and J.M. Lynch, 2002. Strategies for the isolation of cellulolytic fungi for composting of wheat straw. World J. Microbiol. Biotechnol., 18: 471-480.
CrossRef  |  Direct Link  |  

Jaime-Garcia, R. and P.J. Cotty, 2010. Crop rotation and soil temperature influence the community structure of Aspergillus flavus in soil. Soil Biol. Biochem., 42: 1842-1847.
CrossRef  |  

Jin, S. and H. Chen, 2007. Near-infrared analysis of the chemical composition of rice straw. Indus. Crops Prod., 26: 207-211.
CrossRef  |  Direct Link  |  

Kausar, H., M. Sariah, H.M. Saud, M.Z. Alam and M.R. Ismail, 2010. Development of compatible lignocellulolytic fungal consortium for rapid composting of rice straw. Int. Biodeterior. Biodegrad., 64: 594-600.
CrossRef  |  Direct Link  |  

Kim, M.N., A.R. Lee, J.S. Yoon and I.J. Chin, 2000. Biodegradation of poly(3-hydroxybutyrate), Sky-Green® and Mater-Bi® by fungi isolated from soils. Eur. Polymer J., 36: 1677-1685.
CrossRef  |  

Kuhad, R.C., A. Singh and K.E.L. Eriksson, 1997. Microorganisms and enzymes involved in the degradation of plant fiber cell walls. Adv. Biochem. Eng. Biotechnol., 57: 45-125.
CrossRef  |  PubMed  |  

Kumar, A., S. Gaind and L. Nain, 2008. Evaluation of thermophilic fungal consortium for paddy straw composting. Biodegradation, 19: 395-402.
CrossRef  |  

Liang, Y.S., X.Z. Yuan, G.M. Zeng, C.L. Hu and H. Zhong et al., 2010. Biodelignification of rice straw by Phanerochaete chrysosporium in the presence of dirhamnolipid. Biodegradation, 21: 615-624.
CrossRef  |  PubMed  |  

Liu, B., D. Glenn and K. Buckley, 2008. Trichoderma communities in soils from organic, sustainable and conventional farms and their relation with Southern blight of tomato. Soil Biol. Biochem., 40: 1124-1136.
CrossRef  |  

Meriles, J.M., S.V. Gil, C. Conforto, G. Figoni, E. Lovera, G.J. March and C.A. Guzman, 2009. Soil microbial communities under different soybean cropping systems: Characterization of microbial population dynamics, soil microbial activity, microbial biomass and fatty acid profiles. Soil Tillage Res., 103: 271-281.
CrossRef  |  

Minamiyama, H., M. Shimizu, H. Kunoh, T. Furumai, Y. Igarashi, H. Onaka and R. Yoshida, 2003. Multiplication of isolate R-5 of Streptomyces galbus on rhododendron leaves and its production of cell wall-degrading enzymes. J. Gen. Plant Pathol., 69: 65-70.
CrossRef  |  Direct Link  |  

Oanh, N.T.K., B.T. Ly, D. Tipayarom, B.R. Manandhar, P. Prapat, C.D. Simpson and L.J.S. Liu, 2011. Characterization of particulate matter emission from open burning of rice straw. Atmos. Environ., 45: 493-502.
CrossRef  |  Direct Link  |  

Parr, J.F., R.I. Papendick, S.B. Hornick and R.E. Meyer, 1992. Soil quality: Attributes and relationship to alternative and sustainable agriculture. Am. J. Alter. Agric., 7: 5-11.
CrossRef  |  

Pointing, S.B., 1999. Qualitative methods for the determination of lignocellulolytic enzyme production by tropical fungi. Fungal Diversity, 2: 17-33.
Direct Link  |  

Porras, M., C. Barrau and F. Romero, 2007. Effects of soil solarization and Trichoderma on strawberry production. Crop Prot., 26: 782-787.
CrossRef  |  

Qiao, H., C. Tian, Y. Luo, J. Sun and X. Feng, 2008. Diversity of soil microorganisms in natural populans euphratic forest in Xinjiang, North Western China. Frontiers For. China, 3: 347-351.
CrossRef  |  

Reanprayoon, P. and W. Yoonaiwong, 2012. Airborne concentrations of bacteria and fungi in Thailand border market. Aerobiologia, 28: 49-60.
CrossRef  |  

Rodriguez, A., A. Moral, R. Sanchez, A. Requejo and L. Jimenez, 2009. Influence of variables in the hydrothermal treatment of rice straw on the composition of the resulting fractions. Bioresour. Technol., 100: 4863-4866.
CrossRef  |  Direct Link  |  

Shukla, N., R.P. Awasthi, L. Rawat and J. Kumar, 2012. Biochemical and physiological responses of rice (Oryza sativa L.) as influenced by Trichoderma harzianum under drought stress. Plant Physiol. Biochem., 54: 78-88.
CrossRef  |  

Stepanova, E.V., O.V. Koroleva, L.G. Vasilchenko, K.N. Karapetyan and E.O. Landesman et al., 2003. Fungal decomposition of oat straw during liquid and solid state fermentation. Appl. Biochem. Microbiol., 39: 65-74.
CrossRef  |  

Tortella, G.R., O. Rubilar, L. Gianfreda, E. Valenzuela and M.C. Diez, 2008. Enzymatic characterization of Chilean native wood-rotting fungi for potential use in the bioremediation of polluted environments with chlorophenols. World J. Microbiol. Biotechnol., 24: 2805-2818.
CrossRef  |  Direct Link  |  

Toyama, H. and N. Toyama, 2001. The effect of additional autopolyploidization in a slow growing cellulase hyperproducer of Trichoderma. Applied Biochem. Biotechnol., 91-93: 787-790.
CrossRef  |  PubMed  |  

Wang, Y., J. Xu, J. Shen, Y. Luo, S. Scheu and X. Ke, 2010. Tillage, residue burning and crop rotation alter soil fungal community and water-stable aggregation in arable fields. Soil Tillage Res., 107: 71-79.
CrossRef  |  

Watanabe, T., 2002. Trichoderma harzianum: Pictorial Atlas of Soil and Seed Fungi Morphologies of Cultured Fungi and Key to Species. 2nd Edn., CRC Press, New York.

Whitelaw-Weckert, M.A., L. Rahman, R.J. Hutton and N. Coombes, 2007. Permanent swards increase soil microbial counts in two Australian vineyards. Applied Soil Ecol., 36: 224-232.
CrossRef  |  

Xu, C., M. Long, X. Wu, H. Xu, Z. Chen, F. Zhang and L. Xu, 2006. Screening and characterization of the high-cellulase-producing strain Aspergillus glaucus XC9. Front. Biol. China, 1: 35-40.
CrossRef  |  

Xu, J. and Q. Yang, 2010. Isolation and characterization of rice straw degrading Streptomyces griseorubens C-5. Biodegradation, 21: 107-116.
CrossRef  |  PubMed  |  

Xu, Z.H., Y.L. Bai, X. Xu, J.S. Shi and W.Y. Tao, 2005. Production of alkali-tolerant cellulase-free xylanase by Pseudomonas sp. WLUN024 with wheat bran as the main substrate. World J. Microbiol. Biotechnol., 21: 575-581.
CrossRef  |  Direct Link  |  

Yang, S.S., H.Y. Fan, C.K. Yang and I.C. Lin, 2003. Microbial population of spruce soil in Tatachia mountain of Taiwan. Chemosphere, 52: 1489-1498.
CrossRef  |  PubMed  |  

Yu, H., G. Zeng, H. Huang, X. Xi, R. Wang and D. Huang et al., 2007. Microbial community succession and lignocellulose degradation during agricultural waste composting. Biodegradation, 18: 793-802.
CrossRef  |  PubMed  |  

©  2020 Science Alert. All Rights Reserved