Diversity of cultivable bacteria from deep-sea sediments of the Colombian Caribbean and their potential in bioremediation.

The diversity of deep-sea cultivable bacteria was studied in seven sediment samples of the Colombian Caribbean. Three hundred and fifty two marine bacteria were isolated according to its distinct morphological character on the solid media, then DNA sequences of the 16S rRNA were amplified to identify the isolated strains. The identified bacterial were arranged in three phylogenetic groups, Firmicutes, Proteobacteria, and Actinobacteria, with 34 different OTUs defined at ≥ 97% of similarity and 70 OTUs at ≥ 98.65%, being the 51% Firmicutes, 34% Proteobacteria and 15% Actinobacteria. Bacillus and Fictibacillus were the dominant genera in Firmicutes, Halomonas and Pseudomonas in Proteobacteria and Streptomyces and Micromonospora in Actinobacteria. In addition, the strains were tested for biosurfactants and lipolytic enzymes production, with 120 biosurfactant producing strains (mainly Firmicutes) and, 56 lipolytic enzymes producing strains (Proteobacteria). This report contributes to the understanding of the diversity of the marine deep-sea cultivable bacteria from the Colombian Caribbean, and their potential application as bioremediation agents.

Prevalence of microplastic contamination in the digestive tract of fishes from mangrove ecosystem in Cispata, Colombian Caribbean.

Plastics in Colombian marine-coastal ecosystems are being fragmented by various environmental factors, generating microplastics (size < 5 mm), an emerging pollutant that is ingested by marine organisms, representing a threat to ecosystems and potentially also to humans. This study aims to evaluate the incidence of microplastic ingestion by fishes from mangrove ecosystems in Cispata, Colombian Caribbean. The digestive tract content of 302 specimens of 22 fish species were analyzed using the KOH digestion method (500 g/5 L), stereoscopic visual identification and infrared spectroscopy. A total of 69 microplastics were found in the digestive tract of 7% of the analyzed fishes. 55% of the ingested microplastics were filaments, 23% fragments, 19% films, and 3% foam. The results of this study raised concerns about microplastic contamination in the marine environments, a threat to the fishery resource and to public health, which requires actions to prevent and reduce its negative effects.

Milk kefir: composition, microbial cultures, biological activities, and related products.

In recent years, there has been a strong focus on beneficial foods with probiotic microorganisms and functional organic substances. In this context, there is an increasing interest in the commercial use of kefir, since it can be marketed as a natural beverage that has health promoting bacteria. There are numerous commercially available kefir based-products. Kefir may act as a matrix in the effective delivery of probiotic microorganisms in different types of products. Also, the presence of kefir's exopolysaccharides, known as kefiran, which has biological activity, certainly adds value to products. Kefiran can also be used separately in other food products and as a coating film for various food and pharmaceutical products. This article aims to update the information about kefir and its microbiological composition, biological activity of the kefir's microflora and the importance of kefiran as a beneficial health substance.