Isolation and characterization of culturable bacteria from tropical coastal waters

Abstract

In this study we isolated and characterized some culturable bacteria from tropical coastal waters of Peninsular Malaysia. We obtained between 0.23 and 1.85 × 10 3 cfu mL −1 in the Zobell 2216E medium, and cultured 0.04% to 0.12% of total bacterial counts. Different bacterial strains were then selected by 16S rDNA RFLP using four restriction enzymes (DdeI, HhaI, RsaI, and Sau3AI), of which HhaI gave the most RFLP patterns. A total of 54 unique strains were obtained and these were identified by their 16S rDNA gene sequence. These bacterial strains could be divided into five classes: 38 strains of γ-Proteobacteria (61.1%); 3 strains of α-Proteobacteria (5.5%); 2 strains of the Cytophaga-Flavobacterium-Bacteroides group (3.7%); 3 strains of high GC, Gram-positive bacteria (5.5%); and 13 strains of low GC, Gram-positive bacteria (24.1%). These isolates have good potential for further biotechnological studies since about 56% of the isolates exhibited amylase activity, whereas 36% and 18% of the isolates had protease and lipase, respectively. Most (>70%) of the isolates also produced poly-β-hydroxybutyrate.Key words: 16S rDNA RFLP, marine bacteria, South China Sea, Straits of Malacca, ZoBell 2216E. ResumenEn este estudio se aislaron y caracterizaron algunas bacterias cultivables de las aguas costeras tropicales de Malasia Peninsular. Se obtuvieron entre 0.23 y 1.85 × 10 3 ufc mL −1 en medio de cultivo Zobell 2216E, y se cultivaron 0.04% a 0.12% de los conteos totales de bacterias. Se seleccionaron diferentes cepas bacterianas mediante RFLP del gen 16S rDNA usando cuatro enzimas de restricción (DdeI, HhaI, RsaI y Sau3AI), de las cuales HhaI produjo más patrones de RFLP. Se obtuvieron un total de 54 cepas singulares, las cuales fueron identificadas por su secuencia 16S rDNA. Estas cepas bacterianas fueron divididas en cinco clases: 38 cepas de γ-proteobacterias (61.1%), 3 cepas de α-proteobacterias (5.5%), 2 cepas del grupo CytophagaFlavobacter-Bacteroides (3.7%), 3 cepas de bacterias Gram positivas con alto contenido de GC (5.5%) y 13 cepas de bacterias Gram positivas con bajo contenido de GC (24.1%). Estos aislados tienen un buen potencial para futuros estudios biotecnológicos ya que 56% de ellos presentaron actividad de la enzima amilasa, mientras que 36% y 18% presentaron actividad de las enzimas proteasa y lipasa, respectivamente. La mayoría (>70%) de los aislados produjeron poli-β-hidroxibutirato.

Complete degradation of dimethyl phthalate by biochemical cooperation of the Bacillus thuringiensis strain isolated from cotton field soil

“…PCR amplication was carried out according to the following conditions: initial denaturation at 94 C for 2 min; 35 cycles of denaturation for 30 s at 94 C, annealing for 40 s at 55 C, extension for 90 s at 72 C; and a nal extension at 72 C for 7 min. PCR products were then puried using the QIAquick® PCR Purication Kit (QIAGEN, Germany) as reported earlier by Lee et al 23 The 16S rDNA sequences of each isolates were compared to GenBank entries using Basic Local Alignment Tool (BLAST) in order to obtain a preliminary affiliation.…”

Bacteriological Monitoring and Sustainable Management of Beach Water Quality in Malaysia: Problems and Prospects

“…For most of the studies considered in this review, the choice of bacteriological parameters used was largely conventional faecal indicator bacteria. Lee et al (2009) reported a study on characterization of culturable bacteria from selected coastal environments along the Straits of Malacca. Using an approach based on 16S rDNA restriction fragment length polymorphism (RFLP), and 16S rDNA sequence analysis, the study determined the bacterial diversity in these coastal waters presenting a comparison analysis of culturable versus unculturable bacteria.…”

Bioprospecting of extremophilic perchlorate-reducing bacteria: report of promising Bacillus spp. isolated from sediments of the bay of Cartagena, Colombia

“…Some autochthonous extremophile strains generate biohydrogen as a substrate to treat organic waste to survive and use the macromolecules present in polluted marine environments as a carbon source (Oguntoyinbo 2007 ; Lee et al 2009 ). In fact, halophytes strains are examples of extremophile microorganisms found in marine environments, with a remarkable ability to withstand harsh conditions and decontaminate the environment.…”