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  Traditional dairy products harbor a complex microbiota composed by several microbial groups, including lactic acid bacteria (LAB) and yeasts. The common method to detect LAB is to culture the products on media containing cycloheximide (CHX) to prevent yeast growth by interfering with protein synthesis. However, some yeast species and strains show natural or acquired resistance to this antibiotic and thus can be specifically selected in media with CHX. The aim of this research was to identify such CHX-resistant yeasts. To this purpose, 25 samples of home-made dairy products were plated on MRS medium with 0.01% CHX; after incubation (48 h, 30˚C), 32 colonies of presumptive yeasts were picked up. Catalase test and morphological investigation confirmed that 19 were yeasts. After DNA isolation, randomly amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) with primer M13 was applied to gain information on genomic relatedness among isolates. Visual comparison of RAPD-PCR pattern allowed selecting five representative isolates for further analysis. Primers ITS1 and ITS4 were used for specific amplification, and the PCR-products were sequenced after purification. The results of sequencing revealed that all isolates belong to Kluyveromyces marxianus, a species with a high technological potential.  

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Evaluation of the antimicrobial activity of bacteria in the aquaculture ecosystem is the first stage of probiotic bacteria screening studies. The aim of the present study was to isolate the intestinal bacteria of cultivated Vanammei shrimp with antimicrobial activity against pathogenic bacteria in vitro and in vivo. For this purpose, sampling of shrimp culture sites in South Tiab and North Tiab was done in 3 stages. The results of counting culturable bacteria using Zobell agar culture medium showed that in South Tiab site, the average number of bacteria in shrimp intestine samples was from 3.66 × 10⁶ CFU/gr in the first stage of sampling to 4.63 ×10⁶ CFU/gr in the third stage. With a similar trend, the changes of this amount in the North Tiab site fluctuated from 16.4 ×10⁶ CFU/gr to 16.16 ×10⁶ CFU/gr. Evaluation of the antimicrobial activity of the isolates using the agar diffusion method showed that 9, 6, 4 and 3 isolates respectively compared to V. alginolyticus, V. harveyi, V. parahaemolyticus and P. aeroginosa showed antimicrobial activity.

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Iran stands out as a significant center of genetic diversity for alfalfa (Medicago sativa) worldwide, harboring diverse types of this plant. Ensuring the authenticity of alfalfa populations and varieties is crucial for farmers and seed producers, as the genetic makeup of this species directly influences forage and seed yield quality. In this study, we developed a method to identify and differentiate key Iranian cultivated alfalfa populations using microsatellite markers. We collected random samples, each containing 100 seeds, from various alfalfa accessions. Nine microsatellite loci were screened and employed to differentiate these populations based on specific allelic genotypes. Notably, the MTIC233, BI90, ACT009, TC7, MTIC183, MS30, MTIC238, and AFCA11 markers exhibited the highest differentiation ability. The genetic distance analysis revealed that 5-B and foreign accessions, as well as 29-N and foreign accessions, were the most distant from each other. Conversely, 27-G, 9-H, and 21-R exhibited the closest genetic similarity. The results revealed that, accessions 9-H, 21-R, 27-G, 25-B, 5-B, and 2-G shared a common genetic background, suggesting their close relatedness. Our proposed method allows straightforward identification of target alfalfa accessions within a short timeframe (one to two days) without the need for DNA extraction from leaves.