A novel Thermothelomyces heterothallicus PA2S4T fungus isolated from the soil induces chitinase production using orange peel flour

Chitinases are enzymes capable of hydrolysing the β-1,4 bonds of chitin releasing chitooligosaccharides and N-acetylglucosamine and are widely used in food, pharmaceutical, and agricultural industries. Microorganisms are potential producers of this enzyme; however, there are no reports in the literature on the production of chitinase by fungi of the genus Thermothelomyces. Thus, this work aimed to investigate the production of extracellular chitinase using alternative carbon sources by the fungus isolated from soil, Thermothelomyces heterothallicus PA2S4T. The fungus was cultivated in a liquid medium supplemented with carbon sources and incubated at 40°C under stationary conditions for seven days. Orange peel flour was the best inducer for extracellular chitinase, with 82.3 U/mL of enzymatic activity. The highest production of chitinase was obtained on the tenth day, and the optimum pH and temperature for enzyme activity were 4.5 and 50ºC, respectively. Therefore, the fungus T. heterothallicus PA2S4T proved to be promising in the production of extracellular chitinase, which presents pH and temperature characteristics favourable to biotechnological application.

Characterization of amylase and protease activity in the digestive tract of two teleosts (Labeo rohita and Anabas testudineus) with different feeding habits

Two teleosts (Rohu, Labeo rohita and Koi, Anabas testudineus), both with contrasting feeding habits (herbivorous versus carnivorous) were studied for amylase and protease activity concerning different regions of their digestive tracts. Significant differences in enzymatic activity across different regions of the digestive tracts were observed. Rohu, with three equal regions of the stomachless gut, showed the highest amylolytic activity at the posterior digestive tract but the highest proteolytic activity is limited to mid region. Contrary to such observation, Koi with three distinct regions of the digestive tract (stomach, pyloric caeca and intestine), the pyloric caeca exhibited the highest specific activity for both amylase and total protease. The optimum pH and temperature conditions were determined concerning the activity for both amylase and protease.

Isolation of Corncob Xylan-Degrading Fungi and Its Application in Xylobiose Production

In the present study, a potential corncob xylan degradation fungi was isolated and screened from soil to produce xylanase, and was identified as Fusarium oxysporum. The production of xylanase by F. oxysporum under solid state fermentation using corncob powder as the solid substrate reached the maximum xylanase activity when using particle size of substrate of 60 mesh, water content ratio of 2 mL/g substrate, incubation temperature of 30°C, initial pH of 6.0, size of inoculum of 5x107 spore/3 g substrate, and incubation time of 2 days. The xylanase activity increased about 4 times up to 7.92 U/mL after optimization. The potential application of xylanase of F. oxysporum in hydrolyzing alkali-treated corncob xylan to produce xylobiose was also demonstrated. Hydrolysis of 6% of corncob xylan using 100 U/g substrate of enzyme loading under optimum pH and temperature conditions (pH 5.5 and 50°C, respectively) achieved the yield of xylobiose up to 28.7 g/100 g pure xylan after 12 h incubation. The purification of hydrolysate could retain 91.1% of xylobiose. Further separation step using activated charcoal column chromatography was able to get a pure xylobiose, but could only recover 59.3% of xylobiose.

Indigeneous Streptomyces spp. isolated from Cyperus rotundus rhizosphere indicate high mercuric reductase activity as a pontential bioremediation agent

Rahayu HM, Putri WA, Khasanah AU, Sembiring L, Purwestri YA. 2021. Indigenous Streptomyces spp. isolated from Cyperus rotundus rhizosphere indicate high mercuric reductase activity as a potential bioremediation agent. Biodiversitas 22: 1519-1526. The purification and characterization of mercuric reductase of four indigenous Streptomyces spp. from Cyperus rotundus L. rhizosphere in mercury-contaminated area have been investigated. Cell-free extract was obtained by disrupting cells using sea sand at 4 °C followed by centrifugation. Mercuric reductase was purified by ammonium sulfate precipitation, dialysis, and chromatography column (DEAE Sepharose anion column chromatography). The determination of optimum pH and temperature of mercuric reductase activity was measured based on the number of NADPH2 oxidized to NADP per mg protein per minute using a spectrophotometer. The molecular weight of mercuric reductase was determined using SDS-PAGE. Result showed that the highest specific activity of mercuric reductase was recorded from Streptomyces spp. BR28. The optimum pH and temperature of cell-free extract enzyme mercuric reductase were 7.5 and 80 °C, respectively. The enzyme was purified to 431.87-fold with specific activity 21918.95 U/mg protein. SDS PAGE showed that the molecular weight of mercuric reductase in Streptomyces spp. BR 28 ranged from 50 kDa to 75 kDa. It can be concluded that Streptomyces isolates contain mercuric reductase and have potential as mercury bioremediation agent to overcome mercury contamination in the environment.

Mycotoxin degradation by microbial metabolites

Extracellular metabolites of Gliocladium roseum GRZ7 are able to destroy aflatoxin B1 and zearalenone (by 61.9 and 68%, respectively). The determined optimum pH and temperature confirm the enzymatic nature of these metabolites.

Isolasi Mikroorganisme Potensial Penghasil Lipase dari Limbah Pengolahan Minyak Kelapa Sawit Malinping

AbstrakLipase adalah kelompok enzim yang mengkatalisis hidrolisis rantai panjang trigliserida, lemak, dan minyak menjadi gliserol dan asam lemak dengan adanya air. Sumber lipase untuk industri kebanyakan berasal dari mikroorganisme. Penggunaan lipase pada industri makin meningkat setiap tahunnya meliputi aplikasinya pada industri makanan, pakan, farmasi, pulp, dan kertas, biodiesel, dan industri tekstil. Dalam usaha mendapatkan isolat potensial penghasil lipase untuk hHidrofilisasi serat poliester, pada penelitian ini dilakukan skrining dan isolasi mikroorganisme yang dapat menghasilkan lipase dari limbah pengolahan minyak kelapa sawit di Malinping, Lebak, Banten. Sebanyak 20 isolat bakteri dan 5 isolat jamur yang diperoleh kemudian diuji aktivitas lipasenya menggunakan metode titrasi. Empat isolat bakteri terpilih (Kondensat, Lumpur-Got, Hasil-Buangan, dan Tangki-Crude-Oil) serta lima isolat jamur (Nut-A, Nut-B, Nut-C, Kernel-B, dan Kernel-C) dikarakterisasi pH dan suhu optimum enzimnya. Hasil karakterisasi pH menunjukkan bahwa isolat bakteri Kondensat, Lumpur-Got, Hasil-Buangan, dan Tangki-Crude-Oil mempunyai aktivitas enzim lipase tertinggi pada pH 6. Suhu optimal aktivitas enzim lipase isolat Lumpur-Got-B, Hasil Buangan-B, dan Tangki-Crude-Oil B pada 40 °°C, sedangkan isolat bakteri-Kondensat-B optimal pada suhu 30 °°C. Aktivitas lipase kelima isolat jamur optimal pada pH 6. Suhu optimal aktivitas lipase isolat jamur Nut-A adalah 40 °°C, sedangkan isolat Nut-B, Nut-C, Kernel-B, dan Kernel-C aktivitasnya optimal pada 50 °°C.Abstract Lipase are enzymes that catalyzed the hydrolysis of triglyceride, fats and oils into glycerol and fatty acids in the presence of water. Industrial Lipase source mostly derived from microbes. Each year, the lipase utilization in industry increased, such as application for foods, feeds, pharmacys, pulp and papers, biodiesel, and textile industries. On this study, a total of 20 bacteria and 5 fungi lipase potential producer were screened and isolated from oil palm processing waste in Malinping, Lebak, Banten, which then tested for its activity using titration method. Selected isolates then were characterized for its enzyme optimum pH and temperature. The optimum pH for isolate Kondensat, Lumpur-Got, Hasil-Buangan and Crude-Oil-Tank lipases are at pH 6, whilst the optimum temperature of isolates Lumpur-Got B, Hasil-Buangan B and Crude-Oil-Tank B were at 40 °°C and bakteri-Kondensat B isolate optimum at 30 °°C. The five fungi characterization shown optimum pH at 6 and 50 °°C except for isolate Nut-A that optimum at 30 °°C.

Investigation of Optimal Conditions for Production, Characterization, and Immobilization of Fructosyltransferase and β-Fructofuranosidase by Filamentous Fungi

This work's objective was the extracellular production, partial characterization, and immobilization of the enzymes fructosyltransferase (Ftase) and β-fructofuranosidadase (Ffase) by filamentous fungi. Aspergillus niger ATCC 9642 and Penicillium brasilianum were evaluated for the production of fructosyltransferase (Ftase) and β-fructofuranosidadase (FASE) enzymes. The A. niger presented the highest activity of FTase (24.86 µmol/min.mL) and FFase (28.68 µmol/min.mL) in medium composed of 20% sucrose, 0.5% yeast extract, 1% NaNO3, 0.05% MgSO4.7 H2O, 0.25% KH2PO4, 0.5% NH4Cl and 0.25% NaCl inoculated using 5x107spores/mL and incubated at 25°C, pH 5.5, 150 rpm for 48 h. Presenting optimum pH and temperature of 2.39 and 60°C. Thermal stability has shown that the enzyme FFase is more thermally stable when compared to FTase. Stability against different pHs showed similar behavior for FTase and FFase; the optimum pH being between 2.0 and 3.0. FTase and FFase showed storage stability in freezing and refrigeration temperature for approximately 400 h. The kinetic parameters, Km and Vmax, for the sucrose substrate were 24.60mM and 104.16 μmol/min.mL for FTase and 3.91mM and 20.24 μmol/min.mL for FFase. The immobilization process displayed a yield of 6744.66% for FFase and 3928.90% for FTase, with enzymatic activities of 364.79 U/g and 220.34 U/g, and 4 and 3 times reuse, respectively.

pH and Temperature Dependent Gut Enzyme Niche in a Stomachless Herbivorous Freshwater Fish Amblypharyngodon mola (Hamilton, 1822)

The activities of digestive α-amylase (E. C. 3.2.1.1), total proteases, and bile salt-activated lipase (E. C. 3.1.1.-) along the digestive tract (lengthwise divided into five equal parts) of a stomachless freshwater fish (n = 10, weight = 4.354±0.316 g, standard length = 21.641±2.271 cm) were measured at different pH and temperature levels. Different optimum pH and temperature for the activity of α-amylase (8-9, 35°C), proteases (7-8, 45°C), and lipase (8, 45°C) were observed. The first two regions of the digestive tract showed comparatively higher activity of all enzymes. The hierarchical clustering technique revealed three different enzymatically active regions, more inclined to pH in the digestive tract of the studied fish. The present study also supports that the stomachless gut of A. mola has substantial resemblances to the intestinal part of the digestive tract of fish.

Production of N-acetylglucosamine from shrimp shells’ chitin using intracellular chitinase from Mucor circinelloides

Chitin is a natural biopolymer found in shrimp shells and can be processed into Nacetylglucosamine which is extensively used as a dietary supplement to treat osteoarthritis, back pain and knee pain. This research was conducted to determine the optimum pH, temperature, substrate concentration and incubation period to produce Nacetylglucosamine using crude and semi pure intracellular chitinase extracted from Mucor circinelloides. Chitinase activity was measured to determine optimum pH and temperature by using various pHs (3, 4, 5, 6, 7, 8 and 9) and temperatures (30oC, 40oC, 50oC, 60oC, 70oC and 80oC). Different substrate concentrations (0.5%, 1.0%, 1.5% and 2.0%) and incubation periods (2, 4, 6 and 24 hrs) were used to determine the optimum condition to produce N-acetylglucosamine. Results showed that crude intracellular chitinase had an optimum pH of 5 with chitinase activity of 4.16±0.07 U/mL and optimum temperature of 60oC with chitinase activity of 4.22±0.07 U/mL. The optimum substrate concentration obtained was 0.5% and the optimum incubation period obtained was 6 hrs with about 961.67±9.13 ppm N-acetylglucosamine produced. Semi pure intracellular chitinase had an optimum pH of 4 with chitinase activity of 4.75±0.09 U/mL and optimum temperature of 50oC with chitinase activity of 5.03±0.08 U/mL. The optimum substrate concentration obtained was 1.5% and the optimum incubation period obtained was 4 hrs with about 1150.56±12.55 ppm N-acetylglucosamine produced.

Production and Characterization of Crude Protease from RS1 Isolate from silage of Floating Bladderwort (Utricularia gibba)

The purpose of this research was to produce and characterizing crude protease from RS1 isolate of swamp plant silage. The optimum production time of RS1 isolate was 40 h. The optimum pH and temperature of protease from RS1 isolate were 10 and 45℃, respectively. Ion Mg3+ increased RS1 protease whereas ion of Na+, K+, Fe2+, and Zn2+ inhibited protease from RS1 isolate. Study on the effect of metals ion indicated that protease from RS1 isolate was metaloenzyme. Based analysis on SDS-PAGE, the molecular weight of RS1 protease had 12 bands with molecular weights ranging from 34.75 kDa to 263.53 kDa.