Rajavat Asha S, Rai Sudheer, Pandiyan Kuppusamy, Kushwaha Prity, Choudhary Prassan, Kumar Murugan, Chakdar Hillol, Singh Arjun, Karthikeyan Nanjappan, Bagul Samadhan Y, Agnihotri Abha, Saxena Anil K
ICAR-National Bureau of Agriculturally Important Microorganisms, Mau, Uttar Pradesh, India.
Amity Institute of Microbial Technology, Amity University, Noida, Uttar Pradesh, India.
J Basic Microbiol. 2020 Feb;60(2):173-184. doi: 10.1002/jobm.201900382. Epub 2019 Oct 30.
Spent mushroom substrate (SMS), a major byproduct of the mushroom industry, is a lignocellulosic biomass, which contains approximately 57-74.3% of holocellulose fraction. This study was aimed at utilizing SMS of Pleurotus florida for recovery of lignocellulolytic enzymes and sugars and also as a substrate for production of cellulolytic enzymes using different isolates of Trichoderma and Aspergillus under solid-state fermentation (SSF). SMS of P. florida extracts contained significant amounts of laccase (3,015.8 ± 29.5 U/g SMS) and xylanase (1,187.9 ± 12 U/g SMS) activity. Crystallinity pattern and chemical changes in SMS revealed that SMS had a lower crystallinity index (34.2%) as compared with the raw biomass (37.8%), which, in turn, helps in enhancing the accessibility of cellulolytic enzymes to holocellulose. Among the isolates, Trichoderma longibrachiatum A-01 showed maximum activity of endoglucanase (220.4 ± 5.9 U/mg), exoglucanase (78.5 ± 3.2 U/mg) and xylanase (1,550.4 ± 11.6 U/mg) while Aspergillus aculeatus C-08 showed maximum activity of cellobiase (113.9 ± 3.9 U/mg). Extraction with sodium citrate buffer (pH 4.8) showed maximum cellulolytic enzyme activity as compared with other solvents tested. Partial purification of endoglucanase, exoglucanase, xylanase, and cellobiase resulted in 56.3% (1,112.5 U/mg), 48.4% (212.5 U/mg), 44% (4,492.3 U/mg), and 62% (705.0 U/mg) yield with an increase by 5.2-, 4.5-, 4.1-, and 5.0-fold as compared with crude extract. The results reveal that SMS from P. florida could be a potential and cost-effective substrate for production of cellulolytic enzymes from T. longibrachiatum A-01 and A. aculeatus C-08.
废弃蘑菇培养料（SMS）是蘑菇产业的一种主要副产品，属于木质纤维素生物质，其全纤维素含量约为57%-74.3%。本研究旨在利用佛罗里达侧耳的废弃蘑菇培养料来回收木质纤维素酶和糖类，同时将其作为固态发酵（SSF）条件下使用不同木霉属和曲霉属菌株生产纤维素酶的底物。佛罗里达侧耳的废弃蘑菇培养料提取物含有大量的漆酶（3015.8±29.5 U/g SMS）和木聚糖酶（1187.9±12 U/g SMS）活性。废弃蘑菇培养料的结晶度模式和化学变化表明，与原始生物质（37.8%）相比，废弃蘑菇培养料的结晶度指数较低（34.2%），这反过来有助于提高纤维素酶对全纤维素的可及性。在这些菌株中，长枝木霉A-01的内切葡聚糖酶（220.4±5.9 U/mg）、外切葡聚糖酶（78.5±3.2 U/mg）和木聚糖酶（1550.4±11.6 U/mg）活性最高，而棘孢曲霉C-08的纤维二糖酶（113.9±3.9 U/mg）活性最高。与其他测试溶剂相比，用柠檬酸钠缓冲液（pH 4.8）提取显示出最高的纤维素酶活性。内切葡聚糖酶、外切葡聚糖酶、木聚糖酶和纤维二糖酶的部分纯化产率分别为56.3%（1112.5 U/mg）、48.4%（212.5 U/mg）、44%（4492.3 U/mg）和62%（705.0 U/mg），与粗提物相比，活性分别提高了5.2倍、4.5倍、4.1倍和5.0倍。结果表明，佛罗里达侧耳的废弃蘑菇培养料可能是长枝木霉A-01和棘孢曲霉C-08生产纤维素酶的一种潜在且具有成本效益的底物。
