Lignocellulolytic Fungi Research Articles

Optimization of effective composting process of oil palm industrial waste by lignocellulolytic fungi

A batch study was carried out to optimize four process parameters such as particle size (1–5 mm), pH (4–7), mix ratio (1:1–1:3) of substrates (empty fruit bunch, EFB and palm oil mill effluent, POME) and supplementary nutrient as non-food cassava starch (0–2 % w/w). The parameters were evaluated based on the results of electrical conductivity, protein content, organic matter and C/N ratio for an effective composting process. The total period of composting was 35–40 days, a shorter time than the traditional composting process (>60 days). The results showed that the 2-mm particle size of EFB was most suitable to grow microbes, gave the highest protein of 85 g kg−1 and degraded fastest (lowest C/N ratio of 16). Substrate ratio 1:3 (EFB and POME) and pH 5.0 were found to be favorable for mature compost through faster degradation (final C/N ratio almost 17) and microbial growth (around 130 g kg−1 of protein). Moreover, non-food cassava used as supplementary nutrients for initial microbial growth was evaluated and did not significantly affect the results.

Lignocellulolytic Activities among Trichoderma Isolates from Lahad Datu, Sabah and Deception Island, Antarctic

Trichoderma species have the potential for application in composting as biological control agents in controlling disease and increasing yield of production in the agricultural industry. The prevalent soil fungus of Trichoderma produces lignocellulolytic enzymes that assist the degradation of woody lignocellulose materials. The aim of the experimental work was to check the potential of lignocellulolytic Trichoderma fungi for the use of rapid composting of oil palm empty fruit bunches fibers. Fifty-two of Trichoderma isolates from Sabah and seven isolates from Antarctic were examined for in-vitro lignocellulolytic activity by assaying their ability to develop dark brown pigments, yellow halo zone, and clear white zone on tannic acid media (TAM) for lignin; Jensen Media (JM) for cellulose; and modified Melin–Nokrans media (MMNM) for starch. The best six Sabah Trichoderma isolates (5D, 10L2, 10P, 5E, 10X, and 10E2) were found to be potential lignocellulolytic agents based on their diameter of halo zone formed on amended media for further testing of in vitro bioconversion of oil palm empty fruit bunches. The diameters of halo zones were measured for the analysis of their ability in degrading lignin, cellulose, and starch. In contrast, Antarctic Trichoderma isolates consistently exhibited lower lignocellulolytic activities based on their smaller diameter of halo zone formed on TAM, JM, and MMNM. Most of the Trichoderma isolates are found to synthesize polyphenol oxidase, endoglucanases, and are able to hydrolyze starch to glucose in the three different media. Thus, the finding shows the potential of these isolates for use in large-scale composting of oil palm empty fruit bunches.

English

Paddy straw pretreated with Coriolus versicolor MTCC 138, is a ligno-cellulolytic fungus,used to enhance its biodegradability. The potential of microbial pretreatment on paddy straw digestibility was investigated at regular intervals of 5, 10, 15, 20 and 25 days by determining the change in proximate (TS% & VS%) chemical composition (cellulose, hemicellulose, lignin and silica content). Results suggest that, 5 days of pretreatment was appropriate. The pretreatment significantly (P ≤ 0.05) reduced the concentrations of cellulose, lignin and silica in the paddy straw by 19.3, 19.1 and 32.5%, respectively. Thepresent data showed that C. versicolor is capable of producing high quantity of ligno-cellulolytic enzymes for the reduction of lignocellulose biomass in less incubation time. However, biogas production was found to increase by 26.2% in 5 days pretreated sample.   Key words: Paddy straw, pretreatment, silica, Coriolus versicolor, biogas production.

Application of Highly Efficient Lignocellulolytic Fungi In Cocomposting of Paddy Straw Amended Poultry Droppings for the Production of Humus Rich Compost

A two-step composting process for the generation of humus-rich manure from paddy straw amended with poultry droppings was investigated in this study. The composting technique consists of two distinct steps. The first step is decomposition of lignocellulosic constituent of paddy straw by white rot fungi Poly-porus versicolor (Pv), Phanerochaete chrysosporium (Pc) and Pleurotus sajor caju (Psc) for five weeks. The second step is the intensive humus synthetic stage of another five weeks. Fresh poultry droppings and decomposing paddy straw at 1:1 ratio (W/W) was incorporated in the second step instead of incorporating at the beginning like in the traditional composting. Analytical results showed maximum degradation of lignin and cellulose was in Pc inoculated composts (13.9%) followed by those of Psc (11.3%), Pv (8.9%) inoculation and uninoculated control (Uc-5.4%) at the end of first step in two-step composting. Similar pattern of decomposition of lignin and cellulose but in lower magnitude was also observed during the end of first 5 weeks in traditional composting. The content of humic substances (both humic and fulvic acids) in both two-step and traditional composting, was in agreement with the lignin/cellulose degradation rate of those composting systems by respective inoculation. However, the cation-exchange-capacity (CEC) and the content of humic substances were much higher in composts produced in two-step composting than traditional composting. Carbon turnover was remarkable in traditional composting in all inoculated compost series. Two-step composting as compared to traditional composting maintained the C: N ratio of matured compost in a suitable limit. In this regard Pc inoculated composted series proved to be better. Higher loss in lignin and cellulose and increase in CEC and humic substances as well as better nitrogen conservation in two-step composting, especially with Pc inoculation, were attained. Thus, in this study the effectiveness of this biotechnology in accelerating decomposition as well as humification of lignocellulosic resources was established.

Effect of <i>Pleurotus florida</i> on paddy straw digestibility and biogas production

Biogas production from paddy straw offers a great potential as an alternative to fossilfuels. But, lignin and silica adversely affect the efficient utilization of paddy straw. Henceforth, the potential of biological pretreatment of paddy straw by a lignocellulolytic fungus, Pleurotus florida was investigated whereby the straw was inoculated with different spore concentrations of Pleurotus florida for different durations. Biodegradability of paddy straw was determined at different incubation periods and the selected pretreatment was further used for biogas production studies. An incubation period of 30 days was found to be the optimum pretreatment period in enhancing paddy straw digestibility with 19.3% increase in cellulose and 55.1% decrease in lignin. The biologically degraded paddy straw resulted in 15.4% increase in biogas production than that of the untreated paddy straw. DOI: http://dx.doi.org/10.3126/ijls.v6i1.5550

Generation of a cDNA library reveals the presence of a Ty-1/copia transposon in Phellinus rimosus (Hymenochaetaceae, Basidiomycota)

Lignocellulolytic fungi have significant potential as bio-convertors with a particular capacity to degrade recalcitrant natural composts, such as lignin. We generated a cDNA library of a lignocellulolytic fungus, the Phellinus rimosus (Hymenochaetaceae, Basidiomycota), and a typical species of polypore mushroom from the Brazilian semi-arid region. To the best of our knowledge, this is the first report ever to describe the existence of a Ty1-copia retrotransposon in the P. rimosus species. Given the taxonomic complexity in the Brazilian semi-arid region, our findings will be useful as they provide a molecular identity to this important parasite species of the semi-arid region of Brazil. Key words: Lignocellulolytic fungi, biotechnology, Phellinus rimosus, Ty-1 copia, Brazilian semi-arid region, molecular marker.

Fungal biodegradation of genetically modified and lignin-altered quaking aspen (Populus tremuloides Michx.)

AbstractBetter access to wood carbohydrates as a result of reduced, or altered, lignin is a goal of biopulping, as well as biofuel research. In the present article, woods from three transgenic trees and one wild-type quaking aspen (Populus tremuloidesMichx.) were analyzed in terms of mass loss of cellulose and lignin after incubation with lignocellulolytic fungi. The transgenic trees had reduced lignin content through transfer of an antisense -4CL gene, elevated syringyl/guaiacyl (S/G) ratio through insertion of a sense CAld5H gene and low lignin content and elevated S/G ratio through simultaneous insertion of -4CL and CAld5H genes, respectively. The lignocellulolytic fungi employed were a lignin-selective white rot fungusCeriporiopsis subvermispora, a simultaneous white rot fungusTrametes versicolorand a brown rot fungusPostia placenta. Reduced lignin degradation was observed in woods with increased S/G ratios indicating that this analytical feature influences decay resistance, regardless of the fungal decay mechanism.

Effect of inoculation with Penicillium expansum on the microbial community and maturity of compost

Compost prepared from wheat straw and cattle/chicken mature was inoculated with the lignocellulolytic fungus, Penicillium expansum. Compared to uninoculated compost, the inoculated compost exhibited a 150% higher germination index, more than 1.2 g kg −1-dw of changes in NH 4 + -N concentrations, a ca. 12.0% higher humus content and a lignocellulose degradation that proceeded 57.5% faster. Culture-based determinations of microbial populations demonstrated that aerobic heterotrophic bacteria and fungi were about 1–2 orders of magnitude higher in inoculated than in uninoculated compost. The number of ammonifying, ammonium-oxidizing, nitrite-oxidizing, denitrifying bacteria and cellulose-decomposing bacteria was 6.1–9.0 log 10 CFU g −1-dw, 1.2–4.3 log 10 MPN g −1-dw, 3.5–6.8 log 10 MPN g −1-dw, 3.58–4.34 log 10 MPN g −1-dw, 1.4–3.8 log 10 MPN g −1-dw, and 4.2–8.8 log 10 CFU g −1-dw higher in the compost inoculated with P. expansum.

Use of vinasse and sugarcane bagasse for the production of enzymes by lignocellulolytic fungi

In this present work, three strains of Pleurotus and Trichoderma reesei were cultivated in media with pre-treated bagasse and vinasse. Cellulolytic and lignolytic activities and biomass production were analyzed. The treatment of the bagasse with 2% H2O2 + 1.5% NaOH + autoclave resulted in a greater fiber breakage increasing the cellulose level up to 1.2 times and decreasing 8.5 times the hemicellulose content. This treatment also resulted in a high lignolytic activity for all cultures utilized. T. reesei produced laccase, peroxidase and manganese-peroxidase in all the treatments, having its manganese-peroxidase activity raging from 1.9 to 4.8 times higher than the basidiomycetes.

Enzyme profiling of lignocellulolytic fungi

Lignocellulolytic fungi produce a variety of lignocellulolytic enzymes which are responsible for the biodegradation of lignocellulosic agro-wastes in nature. These enzymes are also useful for biofuel production, bio-bleaching, bio-pulping etc. We have isolated ecodiversely different seventeen fungi from ecorich soils of Gandhinagar region, Gujarat, India. The objective of this work was to study enzyme production profile by lignocellulolytic fungi, using wheat straw as a model agro-waste by solid state fermentation. Most of these lignocellulolytic fungi have been found to express enzyme activities like filter paper activity (FPase), endoglucanase, exocellulase, β-glucosidase, xylanase, glucoamylase, manganese peroxidase (MnP) and protease. Among these, A. niger, A. oryzae and Sporotrichum sp. produce endocellulase and xylanase in significant amount. A. niger and Sporotrichum sp. gave 52.47 U/g and 69.441 U/g endocellulase activity, and 48.107 U/g and 112.649 U/g xylanase activity, respectively. © 2010 International Formulae Group. All rights reserved. Key words - Aspergillus niger, Aspergillus oryzae , Sporotrichum sp., fungal isolation, solid state fermentation, wheat straw

Development of compatible lignocellulolytic fungal consortium for rapid composting of rice straw

An experiment was conducted to evaluate the potential of lignocellulolytic fungi for rapid composting of rice straw. Forty-nine isolates of fungi were isolated from several natural and induced rice straw composting sources. Ten isolates were tested for their potential to decompose lignocellulosic rice straw by assessing their growth rate and biomass production, as well as their ability to decompose lignin and cellulose on rice-straw-powder-amended media. Four isolates (F26, F28, F29, and F44) were selected as potential lignocellulolytic agents for in-vitro compatibility study based on their optimum growth rate, biomass production, and lignocellulolytic activities. Six different interactions were found among four interacting isolates in the form of mutual intermingling, partial mutual intermingling, and inhibition at the contact point. Finally, a consortium of Aspergillus niger (F44) and Trichoderma viride (F26) was tested for in-vitro biodegradation of rice straw. The fungal consortium was able to decompose cellulose, hemicelluloses, lignin, and total carbon significantly ( p ≤ 0.05) over the control. The C/N ratio was reduced to 19.5 from an initial value of 29.3 in three weeks of the biodegradation process, thus showing the potential of this method for use in large-scale composting of rice straw.

New records of lignocellulolytic fungi (Basidiomycetes) from the Atlantic Rain Forest in State of Santa Catarina, Brazil

Ten new records of Auriculariales, Hymenochaetales, and Polyporales are reported and added to the checklist of the lignocellulolytic Basidiomycetes species of the Atlantic Rain Forest in Southern Brazil (State of Santa Catarina). Trechispora mollusca (Pers.) Liberta is reported for the first time to Brazil.

Biodelignification and humification of horticultural plant residues by fungi

The degradation of lignin in mixtures of horticultural plant residues with different C/N ratios by lignocellulolytic fungi was evaluated. Sterile sun-dried horticultural wastes were inoculated with Coriolus versicolor, Phanerochaete flavido-alba and Trichoderma koningii under controlled laboratory conditions and the fungal ligninolytic abilities compared and correlated with the humification process. The three fungi enhanced the formation of polymerized molecules, showing a trend similar to that commonly observed in soil humification processes. Lignin was degraded by all three, but to different degrees dependent on fungus and substrate composition. P. flavido-alba was the most active degrader, with a maximum lignin degradation rate of 46%. The efficiency of degradation was affected by the C/N ratio of the substrate, which was adjusted between 21 and 35 by addition of sawdust. Data showed that the tested fungi were effectively involved in humification and lignin degradation of horticultural wastes and might be used as inocula in a pre-treatment process before composting in order to reduce the resistance of the substrate to biodegradation.

Degradation of nitrocellulose by fungi

Three lignocellulolytic fungi, Trametes versicolor, Pleurotus ostreatus, and Coprinus cinereus, and two cellulolytic fungi Trichoderma reesei and Chaetomium elatum were tested for their ability to degrade nitrocellulose. They were provided with different carbon and nitrogen sources in liquid cultures. Nitrocellulose (N content above 12%) was added as nitrogen source (in solution in acetone) alongside amino acids or as sole N source. Either starch or carboxy-methyl cellulose were provided as carbon sources. After 28 days of growth the highest decrease of nitrocellulose was observed with Chaetomium elatum when up to 43% was degraded in a medium containing nitrocellulose as the only nitrogen source. Coprinus cinereus caused a 37% decrease of nitrocellulose when provided with amino acids and starch as co-substrate. In cultures of Trametes versicolor, Pleurotus ostreatus and Trichoderma reesei, only 10%-22% decrease of nitrocellulose was measured in all media. In the presence of nitrocellulose with N content below 12% supplied as 3 mm pellets as the only carbon source, or with nitrocellulose with carboxy-methyl cellulose, the release of nitrite and nitrate from liquid cultures of Chaetomium elatum was measured. Between 6 and 9 days of growth in these media, an increase in both nitrite and nitrate was observed with a loss in weight of nitrocellulose up to 6% achieved after 34 days. The physical nature of the NC pellets may have reduced the rate of degradation in comparison with supplying NC in solution in the cultures.

Laboratory study of inocula production for composting processes

Six ligno-cellulolytic fungi were tested regarding to examine their capability to grow on agricultural wastes and produce inocula for composting. Two residues were used: pepper plant wastes and almond shell residues. Results showed the latter as the most adequate substrate for growth of fungi tested. On the contrary, Trichoderma koningii, as well as HLC1 and HLC3, both fungi isolated from almond shell wastes, were able to persist in pepper plant wastes. Modifications of aeration and pH significantly influenced growth of Coriolus versicolor, HLC1 and Phanerochaete. flavido alba and P. flavido alba and Phlebia radiata, respectively, while P. flavido alba was the only microorganism whose growth was not significantly altered by temperature. In competitive assays, where fungi were growth together with other species, growth of both microorganisms isolated from almond shell residues, HLC1 and HLC3, were stimulated while T. koningii showed the better results in sterile conditions.

Crystal Structure of the 270 kDa Homotetrameric Lignin-degrading Enzyme Pyranose 2-Oxidase

Pyranose 2-oxidase (P2Ox) is a 270 kDa homotetramer localized preferentially in the hyphal periplasmic space of lignocellulolytic fungi and has a proposed role in lignocellulose degradation to produce the essential co-substrate, hydrogen peroxide, for lignin peroxidases. P2Ox oxidizes d-glucose and other aldopyranoses regioselectively at C2 to the corresponding 2-keto sugars; however, for some substrates, the enzyme also displays specificity for oxidation at C3. The crystal structure of P2Ox from Trametes multicolor has been determined using single anomalous dispersion with mercury as anomalous scatterer. The model was refined at 1.8 Å resolution to R and R free values of 0.134 and 0.171, respectively. The overall fold of the P2Ox subunit resembles that of members of the glucose–methanol–choline family of long-chain oxidoreductases, featuring a flavin-binding Rossmann domain of class α/β and a substrate-binding subdomain with a six-stranded central β sheet and three α helices. The homotetramer buries a large internal cavity of roughly 15,000 Å 3, from which the four active sites are accessible. Four solvent channels lead from the surface into the cavity through which substrate must enter before accessing the active site. The present structure shows an acetate molecule bound in the active site with the carboxylate group positioned immediately below the flavin N5 atom, and with one carboxylate oxygen atom interacting with the catalytic residues His548 and Asn593. The entrance to the active site is blocked by a loop (residues 452 to 461) with excellent electron density but elevated temperature factors. We predict that this loop is dynamic and opens to allow substrate entry and exit. In silico docking of d-glucose in the P2Ox active site shows that with the active-site loop in the closed conformation, monosaccharides cannot be accommodated; however, after removing the loop from the model, a tentative set of protein–substrate interactions for β- d-glucose have been outlined.

Microbial characterization of organic carrier colonization during a model biofiltration experiment.

Dynamic microbial characterization of the colonization of organic carrier during a model biofiltration experiment using methanol as air pollutant. A model biofilter was used in order to characterize the micro-organisms involved in the colonization of a model organic carrier. The model system consisted of closed vial as biofilter, peanut shells as lignocellulosic carrier and methanol as air pollutant. The micro-organisms involved in biofiltration were identified and characterized for their lignocellulolytic and methylotrophic activities. Fungi presented a higher lignocellulolytic activity than bacteria. A steady-state was reached after 15 to 20 days. The consortium naturally associated to peanut shells is limited to few aerobic bacteria and lignocellulolytic fungi. This consortium was able to degrade methanol without external nutrient supply. To our knowledge, this is the first paper that focuses on carrier degradation processes and the micro-organisms involved during the start-up period of a biofiltration process.

Selection and identification of cellulolitic and lignocellulolitic fungi from organic waste of cajuput oil (Melaleuca leucadendron L.) from KPH Gundih, Regency of Grobogan

The aims of this research were isolating and selecting fungi that degrading cellulose and lignocellulose of organic waste from cajuput oil distillation. The research outline is organic waste from cajuput oil distillation contain cellulose and lignocellulose that cause naturally composting process take long time. The difficulty of organic waste decomposition depends on the matters in the tissue. To speed up decomposition process it need microorganism. Fungi have more ability to degrade cellulose and lignocellulose than bacteria. Because of that it was necessary to isolate and select fungi that able to degrade cellulose and lignocellulose of organic waste from cajuput oil distillation. This research was done by isolating and identifying fungi from organic waste from cajuput oil distillation and soil where organic waste from cajuput oil distillation was throw away. The selection cellulolytic fungi by inoculate fungi on CMC agar medium and to select lignocellulolytic fungi by inoculate soil dilution 10-4 to agar medium, which was added with organic waste from cajuput oil distillation. The result showed that total of 6 fungi were isolated from organic waste from cajuput oil distillation and soil where organic waste from cajuput oil distillation was throw away. Aspergillus parasiticus, A. nidulans, and Trichoderma harzianum have ability to degrade cellulose. Fungi that have ability to degrade lignocellulose of organic waste from cajuput oil distillation is A. parasiticus. A. parasiticus more potential degrade cellulose and lignocellulose organic waste from cajuput oil distillation than other fungi that found.

Tratamento do feno de braquiária pelo fungo Pleurotus ostreatus

A inoculação de forragens com fungos lignocelulolíticos é uma opção para melhorar a qualidade destas sem adição de produtos químicos. O tratamento do substrato influencia a ação do fungo e a qualidade final do produto. Neste experimento, aplicaram-se quatro tratamentos (compostagem do feno inteiro, compostagem do feno picado, hidratação do feno em água fria e hidratação do feno em água quente) a um feno de Brachiaria decumbens. Aos tratamentos seguiu-se inoculação com o fungo Pleurotus ostreatus e incubação por 35 dias, sob temperatura controlada. Usou-se o delineamento inteiramente casualizado, com quatro repetições e medidas repetidas. Amostras foram colhidas semanalmente para acompanhar a degradação do substrato, mediante a análise química do feno. Observou-se aumento linear, com o decorrer do tempo, no teor de proteína bruta (PB) e na proporção de lignina na parede celular (LIG-FDN), e decréscimo linear nos valores de fibra em detergente neutro (FDN), celulose e hemicelulose. Não se observou efeito de tratamento no teor de FDA. Os tratamentos com compostagem apresentaram maiores valores de PB, lignina e LIG-FDN e menores de FDN e hemicelulose. Não se observou diferença entre os tratamentos com hidratação. O tratamento do feno de braquiária com o fungo propiciou degradação da fração fibrosa e aumento no teor de PB, com efeito mais intenso nos tratamentos que usaram compostagem. A ação do fungo foi mais efetiva sobre a hemicelulose que sobre os demais componentes da fibra.

Predatory fungi, wood decay, and the carbon cycle

Predatory fungi attack nematodes and other microorganisms using a remarkable array of trapping devices to attract, capture, kill, and digest nematodes for food. The novelty of these relationships, however, has deflected attention from a more fundamental role played by these fungi in the ecosystem. The primary function of predatory fungi appears to be that of wood decay and hence they are cellulolytic or ligno-cellulolytic fungi_that attack other organisms as sources of nitrogen to supplement a primarily carbohydrate (woody) diet. The Carbon to Nitrogen ratio (C:N) of wood is extremely high and nitrogen is the limiting factor for growth of predatory fungi. Predation of nematodes or other organisms adds extra protein (nitrogen) to the system and reduces the C:N to manageable proportions. More importantly, nematode predation, although dramatic, is perhaps of less importance than the ability of wood decay fungi to attack bacteria and perhaps other life forms as nutrient supplements. By definition, therefore, many (most?) wood decay fungi are not saprobes (i.e. living on dead organic material) but are facultative parasites (saprobes that can also parasitize living organisms) for part of their life in which the predatory ‘parasitic’ phase runs parallel to the ‘saprophytic’ wood decay phase and both are essential to success. Based on their roles in building up woody material through mycorrhizal associations, and destroying it through biological decay, it is not surprising that the biomass of fungi in forest soils reaches 90% of the total and exceeds all other micro and meso-organisms combined. Based on the respiration of their massive amounts of hyphal material, fungi are the driving force in the biological component of the terrestrial carbon cycle.