Journal of Microbiology

Journal Article

Identification and characterization of a marine-derived chitinolytic fungus, Acremonium sp. YS2-2: Dawoon Chung , Kyunghwa Baek , Seung Seob Bae , Jaejoon Jung; J. Microbiol. 2019;57(5):372-380. Published online February 26, 2019; DOI: https://doi.org/10.1007/s12275-019-8469-0

Abstract: Chitin is the most abundant biopolymer in marine environments. To facilitate its utilization, our laboratory screened marine-derived fungal strains for chitinolytic activity. One chitinolytic strain isolated from seawater, designated YS2-2, was identified as Acremonium species based on morphological and phylogenetic analyses. Acremonium species are cosmopolitan fungi commonly isolated from both terrestrial and marine environments, but their chitinolytic activity is largely unknown. The extracellular crude enzyme of YS2-2 exhibited optimum chitinolytic activity at pH 6.0–7.6, 23–45°C, and 1.5% (w/v) NaCl. Degenerate PCR revealed the partial cDNA sequence of a putative chitinase gene, chiA, in YS2-2. The expression of chiA was dramatically induced in response to 1% (w/v) colloidal chitin compared to levels under starvation, chitin powder, and glucose conditions. Moreover, the chiA transcript levels were positively correlated with chitinolytic activities under various colloidal chitin concentrations, suggesting that ChiA mediates chitinolytic activity in this strain. Our results provide a basis for additional studies of marinederived chitinolytic fungi aimed at improving industrial applications.

Research Support, Non-U.S. Gov't

NOTE] Chitinibacter suncheonensis sp. nov., a Chitinolytic Bacterium from a Mud Flat in Suncheon Bay: Sung Kyum Kim , Yong Ho Kim , Yu Seok Jeong , Han Beur Na , Jungho Kim , Keun Sik Baik , Han Dae Yun , Jung-Kul Lee , Hoon Kim; J. Microbiol. 2012;50(6):1058-1062. Published online December 30, 2012; DOI: https://doi.org/10.1007/s12275-012-2333-9

Abstract: A chitinolytic bacterium, designated strain SK16T, was isolated from a mud flat in Suncheon Bay, Republic of Korea. Strain SK16T is Gram-negative, strictly aerobic, motile by a polar flagellum, and short rod-shaped. Phylogenetic analyses based on 16S rRNA gene sequences showed that the strain belonged to the genus Chitinibacter and was most closely related to Chitinibacter tainanensis S1T (98.2% similarity). DNA-DNA hybridization analyses showed a low association value of 20.45±4.08% between them. The major cellular fatty acids, the G+C content of the genomic DNA, and the predominant quinone of the strain were summed feature 3 (iso-C15:0 2-OH and/or C16:1 ω7c; 50.5%) and C12:0 (12.5%), 52.26 mol%, and Q-8, respectively. Based on the phylogenetic, chemotaxonomic, and phenotypic properties, strain SK16T represents a novel species of the genus Chitinibacter, for which the name Chitinibacter suncheonensis sp. nov. is proposed. The type strain is SK16T (=KCTC 23839T =DSM 25421T).

Search