Screening and indentification of Acetobacter and Gluconobacter isolated from various sources

Abstract

Screening and identification of acetic acid bacteria isolated from various sources were carried out. One hundred eighty-one isolates were isolated from fruits, flowers, and other materials collected in Thailand. On the basis of their phenotypic and chemotaxonomic characteristics including 16S-23S rDNA restriction pattern analysis and the phylogenetic analysis using 16S rDNA sequences, 53 isolates were identified as A. pasteurianus, 42 as A. orientalis, 2 as A. lovaniensis, 17 as G. oxydans, 12 as G. cerinus, 9 as G frateurii, 7 as G. thailandicus, 21 as Asaia, 14 as Gluconacetobacter, 2 as Swaminatania and 2 as Kozakia. The tested strains of Acetobacter contained ubiquinone-9 as the major quinone while the rests contained ubiquinone-10. The DNA G+C contents of the tested isolates ranged from 52 to 63 mol%. PA 3-3 (Group 1) showed 99.8% similarity of 16S rDNA nucleotide with A pasteurianus TISTR 1056T. KLM13-1, MHM10-1, FBM3-4 and BBM91-1 (Group 2) showed 99.5, 99.4, 99.7, and 99.6% sequence similarities with A. orientalis NRIC 0481T, respectively. Strains LBM3-1 (Group 3) showed 99.8% similarity with A. lovaniensis IFO 13753T. Strain JR70-1. (Group 4) showed 99.8% similarity with G. oxydans NBRC 14819T. Strain AK33-2 (Group 5) showed 99.7% similarity with G. cerinus NBRC 3267T. Strain LD51-1 (Group 6) showed 99.6% similarity with G. frateurii NBRC 3264t. Strain MG71-2 (Group 7) showed 99.8% similarity with G. thailandicus NBRC 100600T. Strain MG71-1 (Group 8) showed 99.7% similarity with As. bogorensis NBRC 12264T. In addition, the novel species were found in Gluconobacter, Gluconacetobacter, Swaminatania and Kozakia. They were differenctiated from the type strains by several phenotypic characteristics and 16S rDNA sequence similarity. AN1-1 (Group 7) showed 98.7% similarity with G. frateurii NBRC 3264T. Strain SIS32-2 (Group 9) showed 97.8% similarity with Ga. liquefaciens IFO 12388T. Strain SI15-1 (Group 10) showed 97.7% similarity with Sw. salitolerans PA51T. CT8-1 (Group 11) showed 96.4% similarity with K. baliensis NRIC 0488T. From A pasterianus (Group 1) 53 isolates, PA 3-3 exhibited a maximum alcohol dehydrogenase activity in acetic acid production from ethanol. This isolate produced high acetic acid 28.87 g/l in the culture broth when grown in medium containing (w/v) 0.5% yeast extract, 4% ethanol and 1% acetic acid at 30C for 3 days.