MnP Activity Research Articles

Degradation of Polypropylene Using Fungal Enzyme As A Sustainable Approach To Management Plastic Waste

Polypropylene (PP) is a major environmental problem in Malaysia because it has been ranked the 28th highest plastic polluter in the world (at 56kg per capita per year) in 2021. Landfilling is one of the most common ways of dealing with plastic because leachate may cause increased probability of cancer and neurological impairment in humans. The use of fungi in mycoremediation makes the process eco-friendly. In addition, fungi have a vast hyphal network and broader metabolic competence. The objective of this study was to investigate fungi remediation of PP via the detection of manganese peroxidase and laccase activity in Bushnell Haas Broth (BHB). PP degradation activity was measured via the activity of laccase and manganese peroxidase at a wavelength of 450nm and 610nm, respectively. Of the 17 species of fungi isolated from the Jeram landfill, 12 species of fungi showed growth in BHB with PP as the sole carbon source. Penicillium sp. 1, Aspergillus sp., Penicillium levitum, Talaromyces louisianensis, Aspergillus tamarii, Cunninghamella bertholletiae, Penicillium sp. 2 and Aspergillus niger demonstrated high and longer laccase activity, and these fungi could be considered as potential fungi. P. levitum, P. janthinellum, Penicillium sp, and T. louisianensis have high and longer MnP activity. In summary, P. levitum and T. louisianensis have a high and long duration of MnP and laccase activity in degrading PP, which can be developed and integrated into plastic waste management.

Screening of White-Rot Fungi Isolates for Decolorization of Pulp and Paper Mill Effluent and Assessment of Biodegradation and Biosorption Processes.

Ten white-rot fungal isolates were evaluated for the decolorization potential of pulp and paper mill effluent. Trametes elegans PP17-06, Pseudolagarobasidium sp. PP17-33, and Microporus sp.2 PP17-20 showed the highest decolorization efficiencies between 42 and 54% in 5 d. To reveal the mechanisms involved in decolorization and assess the long-term performance, PP17-06, which showed the highest decolorization efficiency, was further investigated. It could reduce the ADMI color scale by 63.6% in 10 d. However, extending the treatment period for more than 10 d did not significantly enhance the decolorization efficiencies. The maximum MnP activity of 3.27 U L-1 was observed on the 6 d during the biodegradation. In comparison, laccase activities were low with the maximum activity of 0.38 U L-1 (24 d). No significant LiP activities were monitored during the experiment. Dead fungal biomass showed an optimum decolorization efficiency of 44.18% in 8 d employing the biosorption mechanism. No significant changes in the decolorization efficiency were observed after that, suggesting the equilibrium status was reached. These results revealed that PP17-06 has the potential to decolorize pulp and paper mill effluent by employing both biodegradation and biosorption processes.

Feasibility insights into the application of Paenibacillus pabuli E1 in animal feed to eliminate non-starch polysaccharides.

The goal of the research was to find alternative protein sources for animal farming that are efficient and cost-effective. The researchers focused on distillers dried grains with solubles (DDGS), a co-product of bioethanol production that is rich in protein but limited in its use as a feed ingredient due to its high non-starch polysaccharides (NSPs) content, particularly for monogastric animals. The analysis of the Paenibacillus pabuli E1 genome revealed the presence of 372 genes related to Carbohydrate-Active enzymes (CAZymes), with 98 of them associated with NSPs degrading enzymes that target cellulose, hemicellulose, and pectin. Additionally, although lignin is not an NSP, two lignin-degrading enzymes were also examined because the presence of lignin alongside NSPs can hinder the catalytic effect of enzymes on NSPs. To confirm the catalytic ability of the degrading enzymes, an in vitro enzyme activity assay was conducted. The results demonstrated that the endoglucanase activity reached 5.37 U/mL, while beta-glucosidase activity was 4.60 U/mL. The filter paper experiments did not detect any reducing sugars. The xylanase and beta-xylosidase activities were measured at 11.05 and 4.16 U/mL, respectively. Furthermore, the pectate lyase and pectin lyase activities were found to be 8.19 and 2.43 U/mL, respectively. The activities of laccase and MnP were determined as 1.87 and 4.30 U/mL, respectively. The researchers also investigated the effect of P. pabuli E1 on the degradation of NSPs through the solid-state fermentation of DDGS. After 240 h of fermentation, the results showed degradation rates of 11.86% for hemicellulose, 11.53% for cellulose, and 8.78% for lignin. Moreover, the crude protein (CP) content of DDGS increased from 26.59% to 30.59%. In conclusion, this study demonstrated that P. pabuli E1 possesses various potential NSPs degrading enzymes that can effectively eliminate NSPs in feed. This process improves the quality and availability of the feed, which is important for animal farming as it seeks alternative protein sources to replace traditional nutrients.

Removal of triphenylmethane dyes by Streptomyces bacillaris: A study on decolorization, enzymatic reactions and toxicity of treated dye solutions.

This study revealed Streptomyces bacillaris as an efficient biological agent for the removal of triphenylmethane (TPM) dyes. The isolate decolorized Malachite Green (MG), Methyl Violet (MV), Crystal Violet (CV), and Cotton Blue (CB) effectively. S. bacillaris in the treated dye solutions were analyzed for enzyme production, and the cell biomass was observed for functional groups and cell morphology. The treated dye solutions were also analyzed for degraded compounds and their toxicity. Results revealed high decolorization activities for MG (94.7%), MV (91.8%), CV (86.6%), CB (68.4%), attributed to both biosorption and biodegradation. In biosorption, dye molecules interacted with the hydroxyl, amino, phosphoryl, and sulfonyl groups present on the cell surface. Biodegradation was associated with induced activities of MnP and NADH-DCIP reductase, giving rise to various simpler compounds. The degraded compounds in the treated dyes were less toxic, as revealed by the significant growth of Vigna radiata in the phytotoxicity test. There were no significant changes in cell morphology before and after use in dye solutions, suggesting S. bacillaris is less susceptible to dye toxicity. This study concluded that S. bacillaris demonstrated effective removal of TPM dyes via biosorption and biodegradation, rendering the treated dyes less toxic than untreated dyes. Findings in this study enabled further explorations into the potential application of lesser-known actinobacteria (i.e. Streptomyces sp.) for dye removal.

Optimization and Implementation of Fed-Batch Strategy to Produce Ligninolytic Enzyme from the White-Rot Basidiomycete Pycnoporus sanguineus in Bubble Column Reactor

The current work evaluates the production of ligninolytic enzyme optimization via response surface methodology using different inducers: acid cellulignin (CA); MnSO4 (Mn2+); CuSO4·5H2O (Cu2+); veratryl (3, 4-dimethoxybenzyl); alcohol (VA); Tween 80% (T80); and the carbon-to-nitrogen ratio (C/N). A further goal was implementing a fed-batch strategy to produce ligninolytic enzyme extracts from P. sanguineus 2512 using a bubble column reactor (BCR). The best optimized experimental condition in the shake flasks was a 7.5 C/N ratio, 0.025 g/L Cu2+, 1.5 mM Mn2+, 3.0 mM VA and 0.025 mM T80, resulting in 64,580, 9.10 and 80.72 U/L for Laccase (Lac), Manganese (MnP) and Lignin peroxidase (LiP) activities, respectively. In the BCR, three feedings were performed at 24 h intervals on the 6th, 7th and 8th days with a significant increase in Lac (99,600 U/L) and MnP (47.53 U/L) activities on the 8th day and a reduction on the 9th day of cultivation. The LiP activity peak was achieved on the 5th day (416 U/L) of cultivation, decreasing thereafter. Enzyme cocktails concentrated in hollow fiber in the third cultivation batch showed contents of 4 × 105 U/L, 220 U/L and 2.5 g/L for Lac, MnP and total proteins, respectively. The enzymatic cocktail with the highest LiP activity (1200 U/L) was obtained in the first batch. The results showed that the optimization of the biosynthesis of the ligninolytic enzymes provided satisfactory improvement in terms of Lac and MnP production per run.

Isolation, Screening and Identification of Lignin Degraders from the Gut of Termites Odontotermes obesus

The mounting disquiets about the usage of precarious chemicals in the textile industry have steered to the development of eco-friendly and biological methods of fiber processing in the ever-escalating horizon of textile fibers. The current study targets the isolation, identification, and screening of lignin-degrading bacteria from termite gut microflora which could be employed in the textile trade, especially in coir industries for developing a biological method for softening coir fibers. Based on the morphology and taxonomic keys, termites used in the study were identified as Odontotermes obesus. The bacteria isolated from the termite gut having lignolytic activity were picked by using the methylene blue dye decolorizing method. The same was confirmed by using tannic acid. The isolates were then identified as Kosakonia oryzendophytica and Pseudomonas chengduensis by 16s rRNA sequencing. The isolates were further checked for their ability to produce extracellular lignolytic enzymes. The enzyme concentration was found to be significantly higher in the medium containing the microbial consortium than in those with the individual cultures. The consortium filtrate has MnP activity of 41.6 U/mL, LiP activity of 114.3 U/mL, and laccase activity of 61.85 U/mL at 72 hours of incubation. It was found that the enzyme activities were increased considerably until 72 hours of incubation but showed an insignificant increase at 96 hours.

The Manganese Peroxidase Gene Family of Trametes trogii: Gene Identification and Expression Patterns Using Various Metal Ions under Different Culture Conditions.

Manganese peroxidases (MnPs), gene family members of white-rot fungi, are necessary extracellular enzymes that degrade lignocellulose and xenobiotic aromatic pollutants. However, very little is known about the diversity and expression patterns of the MnP gene family in white-rot fungi, especially in contrast to laccases. Here, the gene and protein sequences of eight unique MnP genes of T. trogii S0301 were characterized. Based on the characteristics of gene sequence, all TtMnPs here belong to short-type hybrid MnP (type I) with an average protein length of 363 amino acids, 5–6 introns, and the presence of conserved cysteine residues. Furthermore, analysis of MnP activity showed that metal ions (Mn2+ and Cu2+) and static liquid culture significantly influenced MnP activity. A maximum MnP activity (>14.0 U/mL) toward 2,6-DMP was observed in static liquid culture after the addition of Mn2+ (1 mM) or Cu2+ (0.2 or 2 mM). Moreover, qPCR analysis showed that Mn2+ obviously upregulated the Group I MnP subfamily (T_trogii_09901, 09904, 09903, and 09906), while Cu2+ and H2O2, along with changing temperatures, mainly induced the Group II MnP subfamily (T_trogii_11984, 11971, 11985, and 11983), suggesting diverse functions of fungal MnPs in growth and development, stress response, etc. Our studies here systematically analyzed the gene structure, expression, and regulation of the TtMnP gene family in T. trogii, one of the important lignocellulose-degrading fungi, and these results extended our understanding of the diversity of the MnP gene family and helped to improve MnP production and appilications of Trametes strains and other white-rot fungi.

EFFECT OF SOME AGRO-INDUSTRIAL RESIDUES ON MYCELIAL GROWTH AND PRODUCTION OF LIGNOCELLULOLYTIC ENZYMES BY A FUNGUS NATIVE TO ALGERIAN FOREST

Valorization of agricultural and agro-food by-products by fermentation constitutes a very interesting biotechnological approach for the production of lignocellulolytic enzymes. This work was carried out to reveal the effect of some lignocellulosic materials on the mycelial growth and lignocellulolytic enzymes production by Bjerkandera adusta BRFM 1916. The strain showed ABTS- and guaiacol-oxidation activities. The optimal temperature for mycelial growth was 28 °C. The maximum growth rate of this fungus was achieved on wheat bran (2.08 ± 0.05 cm day-1), followed by barley bran, with a significant reduction of 6.73%. Several agricultural lignocellulosic residues were used as substrates for enzymes production. All the data indicated differential utilization of the various materials by the fungus. The selected fungus produced good CMCase (690 ± 0.066 UL-1) and β-Glu (253 UL-1) activities on wheat bran and orange peels, respectively. A high level of MnP activity (449.21 ± 3.44 UL-1) was obtained on wheat bran.

Bioremediation of polycyclic aromatic hydrocarbons from an aged contaminated agricultural soil using degrading bacteria and soil amendments

The combined effects of degrading bacteria (Paracoccus sp. LXC), humic acid (HA), and soil amendments, including chicken manure, biochar, and wormcast, were investigated through 84 d of incubation in order to improve the remediation of polycyclic aromatic hydrocarbon (PAH) in aged contaminated agricultural soil. PAH concentrations and dissipation kinetics were analyzed, and the biomass and communities of microorganisms and soil enzyme activities were examined to clarify the possible mechanism. The highest removal efficiency of PAHs was 42.1% when treated with Paracoccus sp. LXC combined with biochar and HA. PAH dissipation was consistent with the first-order kinetics model and the half-life of PAHs decreased from 2323.3 d in the natural attenuation to 103–277 d in the amended microcosms. Soil amendments and HA promoted the development of PAH-degrading bacteria and diversity of bacterial communities in soil but not that of fungi. The removal efficiency of PAHs was positively correlated with the density of PAH-degrading bacteria and soil urease (Ure), dehydrogenase (Deh), and manganese-dependent peroxidase (Mnp) activities (r = 0.824–0.941, p < .01). The Paracoccus sp. LXC apparently removed 2–4-ring PAHs, and biochar and wormcast were effective in removing 2–4-ring and 5–6-ring PAHs, respectively. The combined bioremediation strategy using degrading bacteria with soil amendments and HA has high potential for PAH removal in aged contaminated agricultural soil and the possible mechanism was the combination of bioaugmentation with Paracoccus sp. LXC and biostimulation with HA and soil amendments.

Mechanism of lignin degradation via white rot fungi explored using spectral analysis and gas chromatography-mass spectrometry

The mechanism of lignin degradation via white rot fungi was studied. Phanerochaete chrysosporium and Pleurotus ostreatus were used for all the experiments, i.e., measuring the concentration and structure of alkali lignins and studying the effect of the substrate concentration and enzyme activity on the removal. Gas chromatography-mass spectrometry was performed on the reaction liquid of the lignin degradation enzyme system. Alkali lignin had a characteristic absorption spectrum with a peak at approximately 280 nm. Precipitation in the laccase (Lac) degradation system occurred earlier, as well as being more obvious than that in the manganese peroxidase (Mnp) degradation system. The maximum removal was 29.4% in the Mnp degradation system at a concentration of 40 mg/L. The removal increased in a concentration-dependent manner in the Lac degradation system. The increase in Mnp and Lac enzyme activity led to an increased alkali lignin removal. The removal of the control group was significantly lower than the experimental degradation systems. The degradation mainly produced organic acids, esters, and aromatic substances. In conclusion, white rot fungi could effectively remove alkali lignin, in which precipitation played a major role, followed by enzymolysis; the enzymolysis was associated with the alkali lignin concentration and enzyme activity.

Lignocellulolytic enzyme activity pattern of three white oyster mushroom (Pleurotus ostreatus (Jacq.) P. Kumm.) strains during mycelial growth and fruiting body development

Pleurotus ostreatus is one of the edible mushrooms that can utilize lignocellulose as substrate because of their ability to secrete the lignocellulolytic enzyme. The purpose of this research is to investigate and compare the lignocellulolytic enzymes production of P. ostreatus InaCC F209, F216 and LIPI on solid-state fermentation using sawdust during 70 days of mycelial growth (vegetative phase) and fruiting body development (reproductive phase). Supernatant of the extracted enzyme solutions were employed to investigate the reducing sugar, soluble protein, and enzyme activities. The results revealed that reducing sugar concentration of the three P. ostreatus strains subjected increased during growth and reached the maximum concentration on the reproductive phase, while the total protein content fluctuated during the growth but reached the maximum concentration on the reproductive phase. Laccase, LiP, and MnP activities of three P. ostreatus strains were higher on the vegetative phase, while the endoxylanase and endoglucanase activities were higher on the reproductive phase. β-glucosidase activity showed different variations between three P. ostreatus strains. Pleurotus ostreatus InaCC F209 produced the highest and most stable laccase, β-glucosidase, endoglucanase, and endoxylanase than two others.

Biodegradation mechanism of biogas production by modified rice straw fermentation

Based on the literature on the degradation mechanism and the change of micro-functional groups in the fermentation process of modified rice straw, this study aimed to solve the problems of low biogas production rate and poor stability of the biogas production system. In this work, mathematical equations were developed and combined with duck dung and rice straw mixed raw material to perform a fermentation test. The molecular micro-functional group changes of cellulose, hemicellulose, and lignin were studied to obtain the optimal ratio of mixed raw materials for fermentation and to explore the optimization mechanism of its fermentation biogas production. Experimental results showed that the optimal ratio of mixed raw materials was 2.8:1, and the inclusion of a suitable amount of Mn2+(concentration of 2 mol × L-1) was able to strengthen MnP activity and improve the ability of white-rot fungi to rupture β-O-4 bonds. A modification pre-treatment via activated carbon-based solid acid was performed, and the experimental group generated 15.8% more cumulative biogas than the control group. The biogas yield reached its peak when 300 g of inoculum was added to the pre-treatment at a concentration of 30%.

Characterization of Ligninolytic Bacteria and Analysis of Alkali-Lignin Biodegradation Products.

Ligninolytic bacteria degrading lignin were isolates and identified, and their biodegradation mechanism of alkaline-lignin was investigated. Four strains with lignin degradation capability were screened and identified from the soil, straw, and silage based on their decolorizing capacity of aniline blue and colony size on alkaline-lignin medium. The degradation ratio of Bacillus aryabhattai BY5, Acinetobacter johnsonii LN2, Acinetobacter lwoffii LN4, and Micrococcus yunnanensis CL32 have been assayed using alkaline-lignin as the unique carbon source. Further, the Lip (lignin peroxidase) and Mnp (manganese peroxidase) activities of strains were investigated. Lip activity of A. lwoffii LN4 was highest after 72 h of incubation and reached 7151.7 U · l–1. Mnp activity of M. yunnanensis CL32 was highest after 48 h and reached 12533 U · l–1. The analysis of alkaline-lignin degradation products by GC-MS revealed that the strains screened could utilize aromatic esters compounds such as dibutyl phthalate (DBP), and decomposite monocyclic aromatic compounds through the DBP aerobic metabolic pathway. The results indicate that B. aryabhattai BY5, A. johnsonii LN2, A. lwoffii LN4, and M. yunnanensis CL32 have high potential to degrade alkaline-lignin, and might utilize aromatic compounds by DBP aerobic metabolic pathway in the process of lignin degradation.

Statistical optimization of cultural variables for enzymatic degradation of aflatoxin B1 by Panus neostrigosus

The aim of this study is to determine the best aflatoxin B1 degradation conditions which was optimized using a combination of the Plackett-Burman and Box-Behnken methods with Panus neostrigosus culture filtrate. Panus neostrigosus was grown in a modified Kirk Broth medium to determine optimal degradation conditions. As a result, aflatoxin B1 was degraded under varying culture conditions. The Plackett-Burman method was designed after sixteen different experiments with fifteen variables. The three most effective variables (Sucrose, yeast extract, wheat bran) were chosen for the Box-Behnken methodology. The aflatoxin B1 degradation rate was 49% in just 1 h exposure to culture filtrate which was obtained under optimal growth conditions; (g-ml/L) sucrose 10, yeast extract 3, wheat bran 3, soytone 5, KH2PO4 2, MgSO4.7H2O 0.5, CaCl2.H2O 0.1, ammonium tartrate 2, trace element solution 10; 28 °C of incubation temperature, medium pH 5, 7.5% inoculum rate, 125 rpm of agitation speed, and a twelve-day incubation period. The SDS-PAGE studies show that the enzyme responsible for AFB1 degradation has 38 kDa molecular weight and has no laccase or MnP activity. To the best of our knowledge, this is the first report for AFB1 degradation by Panus neostrigosus.

Light Regulation of Two New Manganese Peroxidase-Encoding Genes in Trametes polyzona KU-RNW027.

To better understand the light regulation of ligninolytic systems in Trametes polyzona KU-RNW027, ligninolytic enzymes-encoding genes were identified and analyzed to determine their transcriptional regulatory elements. Elements of light regulation were investigated in submerged culture. Three ligninolytic enzyme-encoding genes, mnp1, mnp2, and lac1, were found. Cloning of the genes encoding MnP1 and MnP2 revealed distinct deduced amino acid sequences with 90% and 86% similarity to MnPs in Lenzites gibbosa, respectively. These were classified as new members of short-type hybrid MnPs in subfamily A.2 class II fungal secretion heme peroxidase. A light responsive element (LRE), composed of a 5′-CCRCCC-3′ motif in both mnp promoters, is reported. Light enhanced MnP activity 1.5 times but not laccase activity. The mnp gene expressions under light condition increased 6.5- and 3.8-fold, respectively. Regulation of laccase gene expression by light was inconsistent with the absence of LREs in their promoter. Blue light did not affect gene expressions but impacted their stability. Reductions of MnP and laccase production under blue light were observed. The details of the molecular mechanisms underlying enzyme production in this white-rot fungus provide useful knowledge for wood degradation relative to illumination condition. These novel observations demonstrate the potential of enhancing ligninolytic enzyme production by this fungus for applications with an eco-friendly approach to bioremediation.

Fungal biosynthesis of lignin-modifying enzymes from pulp wash and Luffa cylindrica for azo dye RB5 biodecolorization using modeling by response surface methodology and artificial neural network

This study demonstrates the evaluation between the artificial neural network technique coupled to the genetic algorithm (ANN-GA) and the response surface methodology (RSM) for prediction of Reactive Black 5 (RB5) decolorization by crude enzyme from Pleurotus. sajor-caju. Fungal lignin-modifying enzymes (FLME) were synthesized using pulp wash (PW) as an inducing substrate, and L. cylindrica (L.C) for cell immobilization. When grown in PW, the fungus showed higher Lac activity (126.5 IU. mL−1), whereas when immobilized a higher MnP activity was achieved (22.79 IU. mL−1), but both methods were capable of decolorizing the dye in about 89.4 % and 75 %, respectively. This indicates applicability of PW as an alternative substrate for FLME induction and viability of immobilization for MnP synthesis. For RB5 decolorization, the action of the crude enzyme extract was considered as a function of pH, dye concentration, temperature, and reaction time. The models are well adjusted to predict the efficiency of biodecolorization, with no statistical difference between ANN-GA and RSM, which indicates potential for green enzymes prospecting application in bioprocess industry.

Enzyme Activity Profiles Produced on Wood and Straw by Four Fungi of Different Decay Strategies.

Four well-studied saprotrophic Basidiomycota Agaricomycetes species with different decay strategies were cultivated on solid lignocellulose substrates to compare their extracellular decomposing carbohydrate-active and lignin-attacking enzyme production profiles. Two Polyporales species, the white rot fungus Phlebia radiata and brown rot fungus Fomitopsis pinicola, as well as one Agaricales species, the intermediate “grey” rot fungus Schizophyllum commune, were cultivated on birch wood pieces for 12 weeks, whereas the second Agaricales species, the litter-decomposing fungus Coprinopsis cinerea was cultivated on barley straw for 6 weeks under laboratory conditions. During 3 months of growth on birch wood, only the white rot fungus P. radiata produced high laccase and MnP activities. The brown rot fungus F. pinicola demonstrated notable production of xylanase activity up to 43 nkat/mL on birch wood, together with moderate β-glucosidase and endoglucanase cellulolytic activities. The intermediate rot fungus S. commune was the strongest producer of β-glucosidase with activities up to 54 nkat/mL, and a notable producer of xylanase activity, even up to 620 nkat/mL, on birch wood. Low lignin-attacking but moderate activities against cellulose and hemicellulose were observed with the litter-decomposer C. cinerea on barley straw. Overall, our results imply that plant cell wall decomposition ability of taxonomically and ecologically divergent fungi is in line with their enzymatic decay strategy, which is fundamental in understanding their physiology and potential for biotechnological applications.

BIODEGRADATION OF BISPHENOL A DURING SUBMERGED CULTIVATION OF TRAMETES VERSICOLOR

Bisphenol A is a persistent chemical, which is widely distributed in the environment despite its short half-life. The continuous release of BPA may cause a chronical exposition of the organisms during sensitive life stages. The chemical possesses not only endocrine disrupting functions but also by oxidative stress may cause damage to the liver cells. In this study the ability of Trametes versicolor 8979 to degrade Bisphenol A during submerged cultivation was exanimated. The chemical was introduced to the medium in 500ppm concentration and the laccase and MnP activities, as well as the residual BPA concentration were monitored. The strain was able to remove completely Bisphenol A from the medium in 6 hours.

Nitrogen sources and trace elements influence Laccase and peroxidase enzymes activity of Grammothele fuligo

The effect of different organic, inorganic nitrogen sources and trace elements on growth and ligninolytic enzymes production by Grammothele fuligo has been investigated. Amongst all the nitrogen compounds used, the most favourable for growth was ammonium oxalate. It showed maximum Lignin Peroxidase activity (80.6 IU/mL) with ammonium chloride. The optimum Manganese Peroxidase activity (4.13 IU/mL) was observed with ammonium acetate. DL-alanine served as the best organic nitrogen source for the growth. The highest MnP (36.7 IU/mL) and laccase (3921.5 IU/mL) activities were revealed in medium supplemented by DL-tryptophan. However, their positive effects on enzyme accumulation were due to a higher biomass production. The higher concentrations of trace elements were found to be fungistatic for its growth viz. B, Co, Cu, Fe (400 ppm) and Co (100 ppm). It exhibited maximum LiP activity (456.9 IU/mL) with 10−3 ppm Fe and MnP activity (3.30 IU/mL) with 10−6 ppm B and 10−3 ppm Ca. The maximum laccase activity (653.5 IU/mL) was observed with 10−6 ppm Cu. This is the first report on nitrogen sources and trace elements effect on ligninolytic enzymes production of Grammothele. The results will facilitate research to understand the nature of the fungus and to increase its enzymes production under controlled conditions.

Use of Palm Empty Fruit Bunches for the Production of Ligninolytic Enzymes by Xylaria sp. in Solid State Fermentation

Palm empty fruit bunches (PEFB) as a cheap substrate for the production of ligninolytic enzymes was investigated using Xylaria sp. BCC 7794 in solid state fermentation. To improve the enzyme production, the optimization was carried out with one factor-at-a-time method. It was found that Xylaria sp. BCC 7794 cultivated in PEFB with the 7% (w/w) wheat starch as co-substrate, the initial moisture content of 70% and the six agar plugs of inoculum for 12 days gave the highest ligninolytic enzymes production. Moreover, the statistic methods using Box-Behnken design was conducted to investigate the optimum nitrogen and CuSO4 concentration for the enzyme production. The maximum laccase and MnP activity of 16.3 and 24.8 U/gPEFB, respectively was achieved at 2.06 g/l (NH4)2H2PO4 (DAHP), 1.07 g/l urea and 5.22 mg/l CuSO4·5H2O. The optimum temperature and pH for the production of ligninolytic enzymes was at 25 °C and pH 5.0–6.0. In addition, it was found that Xylaria sp. BCC 7794 produced hydrolytic enzymes including CMCase, FPase, xylanase and β-glucosidase at 9.93, 0.49, 9.23 and 21.5 U/g PEFB, respectively. Selectivity values of 0.9 was also found with the lignin and cellulose degradation of 16.2 and 18.0%, respectively. PEFB had the potential to use as low cost substrate for the production of ligninolytic enzymes.