Comparative molecular studies of halophilic bacteria from saline water and soil in the Saudi environment / Estudos moleculares comparativos de bactérias halofílicas de água salina e solo no meio ambiente saudita

Halophilic bacteria are microorganisms that grow optimally in the presence of the very high concentration of sodium chloride. Halophiles are vital sources of various enzymes including hydrolases, which are very stable and catalytically highly efficient at high salt concentration and other extreme conditions such as high temperature, pH and presence of organic solvents. Several hydrolases such as amylases, proteases, and lipases have been obtained from halophilic bacteria and are commonly used for various industrial applications. We initiated a screening to isolate and characterize the halophilic bacteria from the Red Sea, which is one of the saltiest bodies of water in the world. Water and soil samples, collected from the Red Sea coast, Jeddah, Saudi Arabia, were screened for isolation of halophilic bacteria. Ten bacterial isolates were obtained, which were characterized by biochemical tests and 16S rRNA gene sequencing. Hydrolase producing bacteria among the isolates were screened by plate assay on starch and gelatin agar plates for amylase and protease, respectively. Two bacterial isolates i.e. Bacillus glycinifermentans S3 and Enterobacter cloacae W1were found to possess significant amylase and protease activity.

Bactérias halofílicas são microrganismos que crescem de maneira ideal na presença de uma concentração muito alta de cloreto de sódio. Halófilos são fontes vitais de várias enzimas, incluindo hidrolases, que são muito estáveis e cataliticamente altamente eficientes em alta concentração de sal e outras condições extremas, como alta temperatura, pH e presença de solventes orgânicos. Várias hidrolases como amilases, proteases e lipases foram obtidas a partir de bactérias halofílicas e são comumente usadas para várias aplicações industriais. Iniciamos uma triagem para isolar e caracterizar as bactérias halofílicas do Mar Vermelho, que é um dos corpos de água mais salgados do mundo. Amostras de água e solo, coletadas na costa do Mar Vermelho, Jeddah, na Arábia Saudita, foram examinadas quanto ao isolamento de bactérias halofílicas. Foram obtidos dez isolados bacterianos, caracterizados por testes bioquímicos e seqüenciamento do gene 16S rRNA. As bactérias produtoras de hidrolase entre os isolados foram triadas por ensaio em placa em placas de amido e ágar de gelatina para amilase e protease, respectivamente. Verificou-se que dois isolados bacterianos, isto é, Bacillus glycinifermentans S3 e Enterobacter cloacae W1, possuíam significativa atividade de amilase e protease.

SNP mapping and phylogenetic analysis of Saudi Arabian horse breeds based on mitochondrial genome sequencing

Arabian horse breeds (Equus caballus L.) are renowned for elegance, endurance and their contribution to Thoroughbreds. In heredity, the mitochondrial (mt) genome is maternally inherited and represents extensive genetic diversity. The mt genomes of Seglawi and Hadban horse breeds of Saudi Arabia were sequenced to decipher the genetic variations in the coding and non-coding regions. We observed that the coding region of mt genome has 11 and 34 amino acid variations in Seglawi and Hadban breeds, respectively. Sequencing analyses of COX1 gene indicated highest variations of which, 5 in Seglawi and 8 in Hadban followed by the NADH5 gene. The mitochondrial genes of respiratory chain showed positive selections with respect to different environments. Our data also highlighted that the Hadban breed had much higher nucleotide changes as compared to Seglawi and together they formed individual branches in phylogenetic tree. However, the tree shows that they were relatively branched to Arabian horse breeds. This study on two Arabian horses shed light on variations among mt genes and their phylogenetic relationship with other horse breeds.