Identification of lactic acid bacteria constituting the predominating microflora in an acid-fermented condiment (tempoyak) popular in Malaysia

Tempoyak is a traditional Malaysian fermented condiment made from the pulp of the durian fruit (Durio zibethinus). Salt is sometime added to proceed f ermentation at ambient temperature. In Various samples obtained from night markets, lactic acid bacteria (LAB) were the predominant microorganisms, ra nging from log 8.4 to log 9.2 cfu g(-1). No other microorganisms were prese nt to such a level. These samples contained reduced amount of saccharose, g lucose and fructose but increased amount of D- and L-lactic acid and acetic acid compared with samples of non-fermented durian fruit. Sixty-four isola tes of LAB were divided into five groups by use of a few phenotypic tests. A total of 38 strains of LAB were selected for comparison by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of their whole cell protein patterns with a SDS-PAGE database of LAB. These strains were also e xamined for their carbohydrate fermentation patterns by use of API 50 CH. I solates belonging to the Lactobacillus plantarum group were Shown to be the predominant members of the LAB flora. In addition, isolates belonging to t he Lactobacillus brevis group, Leuconostoc mesenteroides, Lactobacillus mal i, Lactobacillus fermentum and an unidentified Lactobacillus sp. were also observed. A high degree of diversity among isolates belonging to the Lb. pl antarum group was demonstrated by analysis of their plasmid profiles. (C) 2 001 Elsevier Science B.V. All rights reserved.