• Mycobiology
• /
• 제51권4호
• /
• pp.239-245
• /
• 2023

Xylanase has been applied in various sectors, such as biomass conversion, paper, pulp, textiles, and pharmaceutical industries. This study aimed to isolate and screen potential xylanase-producing fungi from the soil of Suphan Buri Province, Thailand. Fifteen fungi were isolated, and their xylanase activities were tested by the qualitative method. The result showed that isolate SP3, SP10 and SP15 gave high xylanase activity with potency index (PI) of 2.32, 2.01 and 1.82, respectively. These fungi were selected for the xylanase quantitative test, isolate SP10 performed the highest xylanase activity with 0.535 U/mL. Through molecular methods using the 𝛽-tubulin gene, isolate SP10 was identified as Penicillium menonorum. The xylanase characteristics from P. menonorum SP10 were determined, including the xylanase isoforms and the optimum pH and temperature. The xylanase isoforms on SDS-PAGE indicated that P. menonorum SP10 produced two xylanases (45 and 54 kDa). Moreover, its xylanase worked optimally at pH 6 and 55 ℃ while reaching 61% activity at 65 ℃. These results proposed P. menonorum SP10 as a good candidate for industrial uses, especially in poultry feed and pulp industries, to improve yield and economic efficiency under slightly acidic and high-temperature conditions.

• 펄프종이기술
• /
• 제36권3호
• /
• pp.9-14
• /
• 2004

The useful fungi which secret extracellular enzymes was selected for deinking agent of old newsprint. Five fungal strains were isolated from a paper mill soil ground. The CMCase, FPase and xylanase activities of fungi on the liquid culture were investigated at optimal growth conditions. The results of this study were as follow: The optimal pH and temperature for culture growth were 4～8 and 27～$35^{\circ}C$, respectively. For screening of extracellular enzymes at optimal culture conditions the optimal culture period were less than 6-7 days. Fusarium pallidoroseum and Aspergiilus niger which shows relatively higher CMCase, FPase and xylanase activities than the other species were selected for further enzymatic deinking research.

• Journal of Animal Science and Technology
• /
• 제51권5호
• /
• pp.427-432
• /
• 2009

본 연구에서는 xylanase, mannanase를 생산하는 미생물균주를 분리하기 위해 1차로 토양 및 낙엽 등에서 곰팡이 균주를 약 50여주 분리하였으며, 1차 선발된 균주로부터 xylanase, mannanase를 생산하는 미생물 분리를 위해 xylanase 생성균주 선별배지, mannanase 생성균주 선별배지에 single colony를 접종한 후 clear zone이 생기는 15종의 균주를 2차 선발하였다. 2차 선발된 균주를 개별적으로 배양하여, DNS 방법을 활용하여 xylanase, mannanase 효소활성을 측정하여 6종의 균주를 선발하였다. 선별된 균주는 액상배양에서 생산한 xylanase, mannanase 효소활성이 각각 0.9~1.6 unit/mL, 0.2~0.4 unit/mL 범위로 나타났다. 이 중 결과가 좋은 3종을 선정하여 고상배양으로 배양한 균주의 xylanase, mannanase 효소활성은 각각 103.7~220.0 unit/g, 20.1~40.3 unit/g으로 분석되었다. 선별된 3종의 균주중 xylanase, mannanase 효소활성이 각각 197.3 unit/g, 39.9 unit/g으로 가장 높은 E-3 균주를 최종적으로 선발하였다. 최종으로 분리한 E-3 균주는 형태학적 특징과 DNA 염기서열을 비교한 결과 Aspergillus niger와 99% 일치하였다.

• Journal of Microbiology and Biotechnology
• /
• 제12권6호
• /
• pp.890-894
• /
• 2002

A xylanase-producing Trichoderma strain was isolated from soil. Xylanase from Trichoderma strain SY was purified 21-fold to an apparent homogeneity, with a $17.4\%$ yield. The optimum pH and temperature were determined to be 5.5 and $50^{\circ}C$, respectively, and its molecular weight was 21-kDa by SDS-PAGE. The corresponding gene, named xyl, was cloned by RT-PCR. DNA blot analysis of xyl showed that this gene is present as a single copy. The amino acid sequence of the Xyl protein showed similarity to those of other xylanases derived from various fungi. mRNA of xyl was highly expressed when this fungus was grown on cellulose or xylan as a sole carbon source, but undetectable when grown on sucrose. Extracts of Escherichia coli cells expressing xyl were found to have xylanase activity. It was confirmed that xyl from this isolate encodes xylanase.

• Journal of Microbiology and Biotechnology
• /
• 제24권11호
• /
• pp.1559-1565
• /
• 2014

Cellulase and xylanase are main hydrolysis enzymes for the degradation of cellulosic and hemicellulosic biomass, respectively. In this study, our aim was to develop and test the efficacy of a rapid, high-throughput method to screen hydrolytic-enzyme-producing microbes. To accomplish this, we modified the 3,5-dinitrosalicylic acid (DNS) method for microwell plate-based screening. Targeted microbial samples were initially cultured on agar plates with both cellulose and xylan as substrates. Then, isolated colonies were subcultured in broth media containing yeast extract and either cellulose or xylan. The supernatants of the culture broth were tested with our modified DNS screening method in a 96-microwell plate, with a $200{\mu}l$ total reaction volume. In addition, the stability and reliability of glucose and xylose standards, which were used to determine the enzymatic activity, were studied at $100^{\circ}C$ for different time intervals in a dry oven. It was concluded that the minimum incubation time required for stable color development of the standard solution is 20 min. With this technique, we successfully screened 21 and 31 cellulase- and xylanase-producing strains, respectively, in a single experimental trial. Among the identified strains, 19 showed both cellulose and xylan hydrolyzing activities. These microbes can be applied to bioethanol production from cellulosic and hemicellulosic biomass.

• Journal of Microbiology and Biotechnology
• /
• 제21권12호
• /
• pp.1322-1329
• /
• 2011

Filamentous fungi colonizing rice straw were collected from 11 different sites in Korea and were identified based on characterization of their morphology and molecular properties. The fungi were divided into 25 species belonging to 16 genera, including 14 ascomycetes, one zygomycete, and one basidiomycete. Fungal cellulolytic and xylanolytic enzymes were assessed through a two-step process, wherein highly active cellulase- and/or hemicellulase-producing fungi were selected in a first screening step followed by a second step to isolate the best enzyme-producer. Twenty-five fungal species were first screened for the production of total cellulase (TC), endo-${\beta}$-1,4 glucanase (EG), and endo-${\beta}$-1,4 xylanase (XYL) using solid-state fermentation with rice straw as substrate. From this screening, six species, namely, Aspergillus niger KUC5183, A. ochraceus KUC5204, A. versicolor KUC5201, Mucor circinelloides KUC6014, Trichoderma harzianum 1 KUC5182, and an unknown basidiomycete species, KUC8721, were selected. These six species were then incubated in liquid Mandels' media containing cellulose, glucose, rice straw, or xylan as the sole carbon source and the activities of six different enzymes were measured. Enzyme production was highly influenced by media conditions and in some cases significantly increased. Through this screening process, Trichoderma harzianum 1 KUC5182 was selected as the best enzyme producer. Rice straw and xylan were good carbon sources for the screening of cellulolytic and xylanolytic enzymes.

• 한국해양생명과학회지
• /
• 제7권2호
• /
• pp.121-128
• /
• 2022

L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.

• BMB Reports
• /
• 제39권1호
• /
• pp.105-110
• /
• 2006

We have screened 766 strains of fungi from the BIOTEC Culture Collection (BCC) for xylanases working in extreme pH and/or high temperature conditions, the so-called extreme xylanases. From a total number of 32 strains producing extreme xylanases, the strain BCC7928, identified by using the internal transcribed spacer (ITS) sequence of rRNA to be a Marasmius sp., was chosen for further characterization because of its high xylanolytic activity at temperature as high as $90^{\circ}C$. The crude enzyme possessed high thermostability and pH stability. Purification of this xylanase was carried out using an anion exchanger followed by hydrophobic interaction chromatography, yielding the enzyme with >90% homogeneity. The molecular mass of the enzyme was approximately 40 kDa. The purified enzyme retained broad working pH range of 4-8 and optimal temperature of $90^{\circ}C$. When using xylan from birchwood as substrate, it exhibits $K_m$ and $V_{max}$ values of $2.6{\pm}0.6\;mg/ml$ and $428{\pm}26\;U/mg$, respectively. The enzyme rapidly hydrolysed xylans from birchwood, beechwood, and exhibited lower activity on xylan from wheatbran, or celluloses from carboxymethylcellulose and Avicel. The purified enzyme was highly stable at temperature ranges from 50 to $70^{\circ}C$. It retained 84% of its maximal activity after incubation in standard buffer containing 1% xylan substrate at $70^{\circ}C$ for 3 h. This thermostable xylanase should therefore be useful for several industrial applications, such as agricultural, food and biofuel.

• 한국미생물·생명공학회지
• /
• 제48권1호
• /
• pp.38-47
• /
• 2020

본 연구는 토양으로부터 분리한 균주를 대상으로 식물병 방제활성 및 식물 생장촉진 활성을 확인하고자 하였다. 식물병원성 곰팡이에 대한 길항능을 통해 방제기능을 확인할 수 있었으며, 이는 siderophore 및 항생물질 생성 등에 기인되는 것으로 판단된다. 또한 ANG40의 경우에는 amylase, cellulase, xylanase와 같은 세포외 효소활성을 갖고 있음을 확인하였다. 이 외에도 질소 고정능, 인산 가용화능, siderophore 생성능 등 다양한 실험을 통해 식물 생장에 필수적인 질소, 인, 철 등을 식물이 흡수 가능한 형태로 변화시켜 식물 생장에 도움을 줄 수 있을 것으로 기대된다. 또한 6종의 분리균주는 모두 에틸렌 생성과 연관된 IAA를 생성하였으며, 그 중에서도 ANG51의 경우에는 ACC deaminase 활성도 갖고 있음을 확인하였다. 따라서, 최종 선별된 Pseudomonas geniculata ANG3, Exiguobacterium acetylicum ANG40, Burkholderia stabilis ANG51을 이용하여 식물 생장촉진 활성과 식물 병원성 곰팡이에 항진균 활성을 갖는 새로운 생물학적 제제로써 이용 가능성을 제시하였다.