Achmad Dinoto

Bacteroides caecigallinarum sp. nov., isolated from caecum of an Indonesian chicken

Three strains of anaerobic Gram-stain-negative, short to longer rod-shaped bacteria isolated from the caecum of chicken in Indonesia were studied using a polyphasic taxonomic approach. These strains belonged to the genus Bacteroides, based on sequence analysis of 16S rRNA and hsp60 (groEL) genes, with similarities of 93.2-94.1 and 89.8-90.8 %, respectively, to the closest recognized species, Bacteroides coprocola JCM 17929T. Sugar fermentation and enzyme characteristics, cellular fatty acid profiles, menaquinone profiles and metabolic end products were also investigated. Furthermore, DNA-DNA hybridization studies confirmed that the three novel strains are different from the closest related species. The strains were also found to be distinct from each other on the basis of ribotype profiles. The DNA G+C contents of the three strains were 41.1-41.8 mol%. Based on phenotypic and phylogenetic characteristics, a novel species, Bacteroides caecigallinarum sp. nov., is proposed (type strain C13EG111T = LIPI12-4-Ck773T = JSAT12-4-Ck773T = InaCC B455T = NBRC 110959T).

Identification of biofilm-forming bacteria from steel panels exposed in sea waters of Jakarta Bay and Madura Strait

Biofouling formation on marine constructions may cause significant problem such as bridge and vessel damages. Bacterial biofilms are the initiating cause of biofouling. Unfortunately, information of identified biofilm-forming bacteria associated with biofouling process in Indonesian seawaters was still limited. The purpose of this study was to identify biofilm-forming bacteria from biofouling of surface of steel panels exposed in Seawaters of Jakarta Bay and Madura Strait. Steel panels coated either with antifouling or anticorrosion paints were put into sea waters of Jakarta Bay and Madura Strait. Isolation of bacteria was conducted from steel panels fully covered by fouling organisms and on surface without fouling. Confirmation of biofilm-forming activities was performed based on crystal violets-stained bacterial materials on polystyrene well plates. As results, accumulation of macroorganisms and microorganisms was recognized visually on anticorrosion-coated panel that had been put in all observed sea waters for one month. However, biofouling appearances were not recognized on the antifouling-coated panel. Bacterial colonies isolated from Jakarta Bay (108 isolates) and Madura Strait (30 isolates) were screened for biofilm formation on polystyrene well plates. Five isolates representing the most active strain to biofouling activity were then identified based on 16S rRNA gene sequences. As results, isolates of Jakarta Bay C021.MB.1.8, C221.MB.II.11, and C221.MB.II.12 was closely related to Vibrio alginolyticus (99 % similarity). Another two isolates of Madura Strait J111.SM and J111.1.10-6.S had similarity to Vibrio natriegens (99 % to 100 %). All these biofilm-forming bacteria were isolated from biofouling of panels coated with anticorrosion paints. In addition, we confirmed that V. alginolyticus C021.MB.1.8 formed biofilm only if growth medium is seawater from Jakarta Bay. Our study and the bacterial collections will be useful for evaluating and developing new antifouling paints that will be applied in sea waters of these two sites.Biofouling formation on marine constructions may cause significant problem such as bridge and vessel damages. Bacterial biofilms are the initiating cause of biofouling. Unfortunately, information of identified biofilm-forming bacteria associated with biofouling process in Indonesian seawaters was still limited. The purpose of this study was to identify biofilm-forming bacteria from biofouling of surface of steel panels exposed in Seawaters of Jakarta Bay and Madura Strait. Steel panels coated either with antifouling or anticorrosion paints were put into sea waters of Jakarta Bay and Madura Strait. Isolation of bacteria was conducted from steel panels fully covered by fouling organisms and on surface without fouling. Confirmation of biofilm-forming activities was performed based on crystal violets-stained bacterial materials on polystyrene well plates. As results, accumulation of macroorganisms and microorganisms was recognized visually on anticorrosion-coated panel that had been put in all observed sea wa...

Bacteroides caecicola sp. nov. and Bacteroides gallinaceum sp. nov., isolated from the caecum of an Indonesian chicken.

Six strains of anaerobic bacteria, C13EG70T, C13EG118, C13EG186T, C13GAMG5, C13GAMG28 and C13GAMG40, were isolated from the caecum of a healthy chicken bred in Bogor, Indonesia. Phylogenetic analysis showed the isolates were separated into two groups. Group I (C13EG70T and C13EG118) showed nearly identical 16S rRNA gene sequences (99.9 % sequence similarity). Group II (C13EG186T, C13GAMG5, C13GAMG28 and C13GAMG40) showed nearly identical 16S rRNA gene sequences (>99.4 % sequence similarity). The isolates showed low 16S rRNA gene sequence similarities to recognized species of the genus Bacteroides. High gene sequence similarities were found between type strains (C13EG70T and C13EG186T) and Bacteroides salanitronis JCM 13657T (87.9, 91.5 %, respectively). Physiological, biochemical and genotypic characteristics demonstrated that these strains could be separated from the type strain of B. salanitronis. It is concluded that Group I and Group II represent novel species. Two novel species of the genus Bacteroides are proposed as Bacteroides caecicola sp. nov. (type strain C13EG70T = LIPI12-4-Ck732T = JSAT12-4-Ck732T = InaCC B449T = NBRC 110958T) and Bacteroides gallinaceum sp. nov. (type strain C13EG186T = LIPI12-4-Ck844T = JSAT12-4-Ck884T = InaCC B451T = NBRC 110963T).