Abstract. Alyousif NA. 2021. Distribution, occurrence and molecular characterization of Bacillus related species isolated from different soil in Basrah Province, Iraq. Biodiversitas 23: 679-686. Bacillus related species are widely predominant in various environments such as soil with diverse environmental conditions. These bacteria are one of the most explored groups of bacteria in industrial biotechnology due to their enzymes. The present study was aimed to isolate, screen and determine the distribution of Bacillus related species from soil samples. The total Bacillus related species counts in one gram of each soil sample ranged between 3.2 X 103 cfu/g and 4 X 103 cfu/g. A total of 43 isolates with different morphologies were isolated from the soil samples out of ten different habitats and the number of morphotypes recovered from each habitat varied from 2 to 7. The molecular identification of isolates by PCR technique and sequencing of 16S rDNA gene indicated that 43 isolates belonged to the genera Bacillus, Cytobacillus, Priestia and Peribacillus. The species Bacillus licheniformis and Bacillus subtilis were the most distributed species in the habitats. The bacterial isolates were showed 100% similarity, except 8 isolates were showed 99% similarity were identified as new strains and their sequences were deposited at the National Center for Biotechnical Information (NCBI). The phylogenetic tree was constructed by MEGA X software based on 16S rDNA gene sequences of Bacillus related species to evaluate their close relationship and evolution. The study revealed the higher diversity and distribution of Bacillus related species in the soil samples and the molecular technique was the best method for identifying Bacillus related species.

Abstract. Alyousif NA, Luaibi YYYA, Hussein W. 2020. Distribution and molecular characterization of biosurfactant-producing bacteria. Biodiversitas 21: 4034-4040. Biosurfactants (BSs) are biological surface-active compounds produced by several microorganisms with many areas of application, as such become an important product in biotechnology and consequence to be used in industries. In recent years, many researchers pay attention to BSs producers' microorganisms. The present study was aimed to isolate, identify, and screening BS producing bacteria from six various sites in two different cities in Iraq. Four samples were collected from four sites in Basrah governorate and the rest two samples from Al-Garraf oilfield in Thi-Qar governorate. A total of 33 different bacterial isolates were obtained, 20 out of the 33 were found to be biosurfactants producing isolates that detected through the emulsification index (E24%), oil spreading test, and emulsification activity. The isolated bacterial strains were more identified by 16S rRNA gene sequencing. The results showed that the biosurfactants producing isolates belonged to genera Bacillus, Pseudomonas, Enterobacter, Staphylococcus, Acinetobacter, and Aerococcus. Bacillus jeotgali and Aerococcus viridans are reporting as biosurfactant producing bacteria for the first time and Bacillus jeotgali is isolated for first time from crude oil of oilfield reservoir in this study in world. Moreover, six bacterial isolates were identified as new strains and deposited at NCBI Genbank under accession numbers MT261834 (Bacillus subtilis strain IRQNWYA3), MT261835 (Bacillus licheniformis strain IRQNWYB4), MT261836 (Pseudomonas stutzeri strain IRQNWYF2), MT261837 (Pseudomonas zhaodongensis strain IRQNWYF3), MT261838 (Pseudomonas sp. IRQNWYF4) and MT261839 (Bacillus licheniformis strain IRQNWYF5). A2 isolate that was identified as Pseudomonas aeruginosa has shown the highest values of emulsification activity and emulsification index (1.678±0.050 absorbance at 540 nm and 56.6% respectively) that show efficient potential of biosurfactant production. Phylogenetic tree was also constructed in this study based on 16S rRNA gene sequences of biosurfactant-producing bacteria to evaluate their close relationship and evolution between them.

Abstract. Mohammad AJ, Alyousif NA. 2022. Short Communication: Molecular identification and assessment of bacterial contamination of frozen local and imported meat and chicken in Basrah, Iraq using 16S rDNA gene. Biodiversitas 23: 1598-1604. Meat is the main food source of daily meals with highly beneficial effects on human health. It is susceptible to the growth and reproduction of various bacteria due to its composition, which leads to its spoilage, and being an important carrier of pathogenic bacteria. The study aimed to isolate and identify the bacteria contamination of frozen local and imported meat and chicken samples using 16S rDNA gene. Twenty meat samples were collected randomly from local and imported meat sold in markets of Basrah province, Iraq. The results showed that the total aerobic bacteria count was within acceptable limits in all samples. Fifty-seven bacterial isolates were isolated and identified by amplification and sequencing of 16S rDNA gene, where the gram-positive bacteria were the most abundant 34(59.6%), and S. pasteuri is the most common species in the samples with 14 (24%) bacterial isolates out of the total isolates. Fifteen isolates were identified as new strains and their sequences were deposited at GenBank (NCBI) under different accession numbers (MZ964582-MZ964596). The meat and chicken have many bacteria on their surface, therefore the products must be frozen, and sanitary precautions should be taken into consideration.

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Abstract. Alyousif NA, Al-Tamimi WH, Al-sahib MAA. 2022. Evaluation of the effect of various nutritional and environmental factors on biosurfactant production by Staphylococcus epidermidis. Biodiversitas 23: 3533-3538. Biosurfactants are biological surface-active compounds synthesized mainly by hydrocarbon-utilizing bacteria. The properties of biosurfactants make them promising compounds for the application in various fields. The current study evaluated the effect of various nutritional and environmental factors on biosurfactants produced by Staphylococcus epidermidis. This bacterium, for first time in world was isolated from oilfield reservoir in the current study and identified by 16S rDNA sequencing and considered biosurfactant producer according to screening tests. Several factors were evaluated in the current study to assess the optimal conditions for producing the biosurfactant. The results demonstrated that the best carbon source was olive oil with 2% concentration and glutamic acid was the best nitrogen source with 0.2% concentration. The study demonstrated that the best biosurfactant production was recorded at incubation time of 5 days with a 3% inoculum size. Further study is required to determine the chemical structure of produced biosurfactants and to evaluate the potential application of biosurfactants in various fields, therefore constituting a stimulus for future studies.