Chitinase production by endophytic Streptomyces aureofaciens CMUAc130 and its antagonism against phytopathogenic fungi

• Main Authors: Taechowisan T., Peberdy J.F., Lumyong S.
• Format: Article
• Language: English
• Published: 2014
• Online Access: http://www.scopus.com/inward/record.url?eid=2-s2.0-0347028522&partnerID=40&md5=fd7282adff2ba25d022b36091ba3158d; http://cmuir.cmu.ac.th/handle/6653943832/5747
• Institution: Chiang Mai University

More than three hundred isolates of endophytic actinomycetes were screened for their potential for chitinase production. The strain identified as Streptomyces aureofaciens CMUAc130 was the most effective amongst those investigated. This isolate was selected for a more detailed study of chitinase production and its effectiveness in fungal cell wall lysis. Production of the chitinase was optimal with 1% colloidal chitin concentration, at 30-40°C, pH 6.5-7.0 and 100-150 rev min-1 shaking. N-acetylglucosamine was a good inducer and expression of the enzyme complex was repressed by several mono- and disaccharides including lactose, mannose, glucose, cellobiose, arabinose, raffinose, sucrose, xylose and fructose. Addition of pectin, starch and carboxymethyl cellulose to the colloidal chitin-containing medium, increased chitinase production. The enzyme tolerated a wide range of temperature (30-50°C) and pH (5.5-8). Among various divalent cations Hg2+ Cd2+ and Ni2+ completely inhibited the purified enzyme while Mg2+ stimulated its activity. The crude or purified enzyme had potential for cell wall lysis of many phytopathogenic fungi tested.