海洋中のキシラン分解細菌に関する研究-I

Abstract

Various xylan-decomposing microorganisms are known to be widely distributed in the tertestrial environment. A number of organisms and the microbial xylanases have been studied microbiologically or enzymatically by many investigators. However, very little is known on the xylan-decomposing organisms isolated from the marine materials. Therefore, it appears of interest to investigate systematically the xylan-decomposing bacteria and the bacterial xy-lanases in the marine environment. In the first instance of this series, the present investigation was undertaken to establish the optimum conditions for the isolation and enumeration of aerobic β-1, 4'-xylan-decomposing bacteria in the marine environment. From results obtained (Tables 1-9), it was concluded that the most suitable methods for the isolation and enumeration of the xylan-decomposing bacteria from the marine materials, were as follows: 1. The medium was recommended, which contained 10g of β-1, 4'-xylan, 5g of peptone, 1g of yeast extract, (0.1g of ferric phosphate), 10g of agar and 1000ml of filtered sea water, and had a pH of 7.5 after autoclave sterilization. 2. The pour plate method was useful. Namely, every material was diluted successively by powers of 10 with sterilized sea water, and the inoculum diluted appropriately was poured in to the medium, and the inoculated medium was incubated at 25°C for 5 days. Then, among the colonies developed on the plate, the colony surrounded by a halo which was indicative of decomposition of xylan, was enumerated and isolated.