Effect of Alkanes on the Production of a Solvent-stable Extracellular Protease by the Organic Solvent Tolerant Bacterium Bacillus licheniformis YP1 / 微生物学通报

In this paper, the effect of 5% (V/V) n-alkanes (e.g, n-Heptane, n-Octane, n-Decane, n-Dodecanen-Tetradecane and n-Hexadecane) on the growth and protease production of organic-solvent-tolerant- bacte-rium Bacillus licheniformis YP1 was studied. 5%(V/V) n-alkanes had no effect on the stability of YP1 prote-ase. 5% (V/V) n-alkanes had no notable influence on the yield of strain YP1 but dramatically affected theprotease production. The presence of n-Heptane, n-Octane and n-Decane deeply repressed the protease pro-duction; however n-Dodecane, n-Tetradecane and n-Hexadecane enhanced the protease production promi-nencely. The concentration of n-Tetradecane (1%-8%, V/V) had a direct ration with the protease production.The detailed experiments showed that the notable increase of protease activity appeared at the late logarithmof cultivation compared with the blank. The cell shape of YP1 strain remarkably decreased when grown inthe presence of n-Tetradecane. This is the first report about the effect of n-alkanes on the protease productionby the solvent tolerant bacterium.

Identification and Distribution of Hydantoinase-and Carbamoylase-producing Bacteria / 微生物学通报

The isolated 24 strains-producing hydantoinase & carbamoylase were first identified by Biolog microbial identification system and 16S rDNA sequence analysis.The results suggested that the hydantoinase & carbamoyalse-producing bacteria belonged to Bacillus,Geobacillus,Brevibacillus,Aneurinibacillus,Microbacterium,Pseudomonas,Kurthia and Empedobacter,and so on.Especially,Kurthia and Empedobacter were new hydantoinase & carbamoylase-producing genera.Furthuremore,it was found that D-hydatoinase & carbamoyalse-producing bacteria belonged to Pseudomonas and Agrobacterium,while most of L-hydantoinase & carbamoyalse-producing bacterial belonged to Bacillus,Geobacillus and Microbacterium.The distribution feature of D-hydantoinase & carbamoyalse-producing bacteria and L-hydantoinase & carbamoyalse-producing bacteria showed some genera tendency.This research work will provide the biomaterial of different hydantoinase and carbamoylase and contribute to study the structure and function,molecular evolution of the two enzymes.