Biofouling inhibition by Staphylococcus aureus extracts and their potential use for paints / Inhibición de la bioincrustación por extractos de Staphylococcus aureus y su uso potencial para pinturas

For the control of biofouling, some paints based on compounds that are toxic to marine organisms have been used. There is an intensive search for biodegradable solutions that are friendly to non-target organisms. Bacteria have been shown to be a source of compounds with antifouling potential. In this work, the antifouling activity of a strain of Staphylococcus aureus was evaluated. Extracts activity against biofilm-forming bacteria and the toxicity against Artemia franciscana were evaluated. The extracts were incorporated in a hard gel and a paint matrix, and they were exposed to the sea. In both the laboratory and field, we found that the compounds produced by S. aureus have antifouling activity. The non-toxicity of the tested extracts against Artemia franciscana nauplii suggests that the extracts obtained from S. aureus could have a low ecological impact over non-target organisms. Significant differences were found in the percentage of organisms cover in hard gels with extracts and control. After 90 days, important differences were also observed between the percentage of organisms cover of the paints that contained extracts and the control. Dichloromethane extract is the most effective for the inhibition or delay of the settlement of organisms For this reason, they could be used in matrices with different applications, such as in the shipping industry, aquaculture, or any other in which biofouling is a cause of inconvenience.(AU)

Biofouling inhibition by Staphylococcus aureus extracts and their potential use for paints.

For the control of biofouling, some paints based on compounds that are toxic to marine organisms have been used. There is an intensive search for biodegradable solutions that are friendly to non-target organisms. Bacteria have been shown to be a source of compounds with antifouling potential. In this work, the antifouling activity of a strain of Staphylococcus aureus was evaluated. Extracts activity against biofilm-forming bacteria and the toxicity against Artemia franciscana were evaluated. The extracts were incorporated in a hard gel and a paint matrix, and they were exposed to the sea. In both the laboratory and field, we found that the compounds produced by S. aureus have antifouling activity. The non-toxicity of the tested extracts against Artemia franciscana nauplii suggests that the extracts obtained from S. aureus could have a low ecological impact over non-target organisms. Significant differences were found in the percentage of organisms cover in hard gels with extracts and control. After 90 days, important differences were also observed between the percentage of organisms cover of the paints that contained extracts and the control. Dichloromethane extract is the most effective for the inhibition or delay of the settlement of organisms For this reason, they could be used in matrices with different applications, such as in the shipping industry, aquaculture, or any other in which biofouling is a cause of inconvenience.

Depth effect on the prokaryotic community assemblage associated with sponges from different rocky reefs.

Background: Sponge microbiomes are essential for the function and survival of their host and produce biologically active metabolites, therefore, they are ideal candidates for ecological, pharmacologic and clinical research. Next-generation sequencing (NGS) has revealed that many factors, including the environment and host, determine the composition and structure of these symbiotic communities but the controls of this variation are not well described. This study assessed the microbial communities associated with two marine sponges of the genera Aplysina (Nardo, 1834) and Ircinia (Nardo, 1833) in rocky reefs from Punta Arena de la Ventana (Gulf of California) and Pichilingue (La Paz Bay) in the coast of Baja California Sur, México to determine the relative importance of environment and host in structuring the microbiome of sponges. Methods: Specimens of Aplysina sp were collected by scuba diving at 10 m and 2 m; Ircinia sp samples were collected at 2 m. DNA of sponge-associated prokaryotes was extracted from 1 cm3 of tissue, purified and sent for 16S amplicon sequencing. Primer trimmed pair-ended microbial 16S rDNA gene sequences were merged using Ribosomal Database Project (RDP) Paired-end Reads Assembler. Chao1, Shannon and Simpson (alpha) biodiversity indices were estimated, as well permutational analysis of variance (PERMANOVA), and Bray-Curtis distances. Results: The most abundant phyla differed between hosts. Those phyla were: Proteobacteria, Acidobacteria, Cyanobacteria, Chloroflexi, Actinobacteria, Bacteroidetes, and Planctomycetes. In Ircinia sp the dominant phylum was Acidobacteria. Depth was the main factor influencing the microbial community, as analysis of similarities (ANOSIM) showed a significant difference between the microbial communities from different depths. Conclusion: Microbial diversity analysis showed that depth was more important than host in structuring the Aplysina sp and Ircinia sp microbiome. This observation contrast with previous reports that the sponge microbiome is highly host specific.

Marine bacteria associated with shallow hydrothermal systems in the Gulf of California with the capacity to produce biofilm inhibiting compounds.

Shallow hydrothermal systems are extreme environments. The sediments and fluids emitted from the vents present unusual physical and chemical conditions compared to other marine areas, which promotes unique biodiversity that has been of great interest for biotechnology for some years. In this work, a bioprospective study was carried out to evaluate the capacity of bacteria associated with shallow hydrothermal vents to produce biofilm-inhibiting compounds. Degradation assays of N-acyl homoserine lactone (AHL) autoinducers (C6HSL) involved in the quorum sensing process were carried out on 161 strains of bacteria isolated from three shallow hydrothermal systems located in Baja California Sur (BCS), Mexico. The biosensor Chromobacterium violaceum CV026 was used. Twenty-three strains showed activity, and organic extracts were obtained with ethyl acetate. The potential of the extracts to inhibit the formation of biofilms was tested against two human pathogenic strains (Pseudomonas aeruginosa PAO1 and Aeromonas caviae ScH3), a shrimp pathogen (Vibrio parahaemolyticus M8), and two marine strains identified as producing biofilms on submerged surfaces (Virgibacillus sp C29 and Vibrio alginolyticus C96). The results showed that Vibrio alginolyticus and Brevibacillus thermoruber, as well as some thermotolerant strains (mostly Bacillus), produce compounds that inhibit bacterial biofilms (B. licheniformis, B. paralicheniformis, B. firmus, B. oceanizedimenis, B. aerius and B. sonorensis).

Marine Sediment Recovered Salinispora sp. Inhibits the Growth of Emerging Bacterial Pathogens and other Multi-Drug-Resistant Bacteria.

Marine obligate actinobacteria produce a wide variety of secondary metabolites with biological activity, notably those with antibiotic activity urgently needed against multi-drug-resistant bacteria. Seventy-five marine actinobacteria were isolated from a marine sediment sample collected in Punta Arena de La Ventana, Baja California Sur, Mexico. The 16S rRNA gene identification, Multi Locus Sequence Analysis, and the marine salt requirement for growth assigned seventy-one isolates as members of the genus Salinispora, grouped apart but related to the main Salinispora arenicola species clade. The ability of salinisporae to inhibit bacterial growth of Staphylococcus epidermidis, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacer baumannii, Pseudomonas aeruginosa, and Enterobacter spp. was evaluated by cross-streaking plate and supernatant inhibition tests. Ten supernatants inhibited the growth of eight strains of S. epidermidis from patients suffering from ocular infections, two out of the eight showed growth inhibition on ten S. epidermidis strains from prosthetic joint infections. Also, it inhibited the growth of the remaining six multi-drug-resistant bacteria tested. These results showed that some Salinispora strains could produce antibacterial compounds to combat bacteria of clinical importance and prove that studying different geographical sites uncovers untapped microorganisms with metabolic potential.

Marine bacteria from the Gulf of California with antimicrofouling activity against colonizing bacteria and microalgae / Bacterias marinas del Golfo de California con actividad antimicrobiana frente a bacterias colonizadoras y microalgas

Abstract One way of reducing the input of pollutants into the marine environment is to enforce the use of non-toxic antifouling paints in marine protected areas. Thus, the purpose of this study was to detect marine microorganisms that secrete inhibitory substances against bacteria and microalgae to avoid biofouling on manmade structures in La Paz bay, B.C.S., Mexico. The inhibitory potential of 125 bacteria was evaluated against biofilm-forming bacteria. Crude extracts were obtained with methanol and ethyl acetate from 16 bacterial strains that exhibited antagonistic and antibacterial activity in a preliminary screening. Antibacterial and antimicroalgal assays were performed using crude extracts, the minimum inhibitory concentration (MIC) was determined. The highest activity against bacteria and microalgae was found in two strains, Shewanella algae and Staphylococcus sp. The results of this study suggest that extracts of bacteria from the Gulf of California with antimicrobial properties against biofilm-forming bacteria can also prevent the adhesion of microalgae, which may control the development of biofilm formation and, as a consequence, biofouling.(AU)

Resumen Una alternativa para reducir la contaminación en el medio marino es el uso de pinturas anti-incrustantes no tóxicas en áreas marinas protegidas. En el presente estudio se propuso encontrar microorganismos marinos que secreten sustancias capaces de inhibir la adhesión de bacterias y microalgas, de esta manera evitar la bioincrustación en estructuras marinas en la bahía de La Paz, B.C.S., México. Un total de 125 bacterias fueron evaluadas por su capacidad para inhibir el desarrollo de bacterias formadoras de biopelículas. En una selección preliminar de actividad antagónica y antibacteriana, 16 cepas bacterianas mostraron potencial actividad inhibitoria, de las que se obtuvieron los extractos crudos con metanol y acetato de etilo. Se realizaron ensayos antibacterianos y anti-microalgales utilizando los extractos crudos, se determinó la concentración mínima inhibitoria (MIC). Dos cepas mostraron la mayor actividad contra bacterias y microalgas: Shewanella algae y Staphylococcus sp. Los resultados de este estudio sugieren que los extractos de bacterias aisladas en el Golfo de California que poseen propiedades antimicrobianas contra las bacterias formadoras de biofilm y también pueden prevenir la adhesión de microalgas, con lo que se podría controlar el desarrollo de la formación de biopelículas y como consecuencia, el biofouling.(AU)

Amended definitions for Aplysinidae and Aplysina (Porifera, Demospongiae, Verongiida): on three new species from a remarkable population in the Gulf of California.

Verongiid sponges inhabiting the La Paz region, Gulf of California are described herein as new species. Although morphological evidence was sufficient to determine the identity between species, we have confirmed their uniqueness and relationships with molecular (CO1 and ITS1 and 2), and ecological studies. An amended definition of family Aplysinidae and genus Aplysina is presented to highlight a novel skeletal trait for the latter, clearly described herein as a complex of dendritic fibers sustained by anastomosed fibers deep in the choanosome. This novel fiber arrangement combination is a constant trait of Aplysina encarnacionae sp. nov. and A. airapii sp. nov., which otherwise conform to our current concept of Aplysina. The former species has a long tubular morphology, reddish purple color, with the longest dendritic fibers; while A. airapii sp. nov. is a short tubular sponge, yellow with reddish tints, and smaller choanosomal dendritic fibers that depart from a uniplanar anastomosed skeleton. A third species, A. sinuscaliforniensis sp. nov., is characterized by a completely anastomosed skeleton, massive habit with short tubes superimposed one over the other, sympatric with the other new species. Comparisons with Suberea azteca verified that the same novel skeletal architecture described here occurs in the latter, while Aiolochroia thiona examined as well, proved to bear an anastomosed skeleton only, besides sharing more features with Aplysina than with any other genera in Verongiida. Moreover, molecular sequencing recovered "S." azteca nested in the Aplysina clade, prompting us to reallocate it in Aplysina, as originally proposed. The new species described herein are probably endemics within the Gulf of California since they have not been recorded elsewhere along the Mexican Pacific coast.

Seasonal seawater temperature as the major determinant for populations of culturable bacteria in the sediments of an intact mangrove in an arid region.

Mangroves are highly productive marine ecosystems where bacteria (culturable and non-culturable) actively participate in biomineralization of organic matter and biotransformation of minerals. This study explores spatial and seasonal fluctuations of culturable heterotrophic bacteria and Vibrio spp. in the sediments of an intact mangrove ecosystem and determines the dominant environmental factors that govern these fluctuations. Sediment samples were collected monthly from three stations in the mangroves of Laguna de Balandra, Baja California Sur, Mexico, through an annual cycle. Physicochemical parameters included seawater temperature, salinity, and concentration of dissolved oxygen. Viable counts of culturable heterotrophic bacteria and Vibrio spp. were made. In one sample (March 2003), nutrient concentrations (ammonium, nitrites, nitrates, and phosphates), organic matter, pH and sediment texture were also determined. General cluster analyses, analysis of variance of specific variables, and several principal component analyses demonstrated that seawater temperature is the principal determinant of seasonal distribution of culturable heterotrophic bacteria and Vibrio spp. in mangrove sediments. Soil texture, concentration of nutrients, and organic matter concentration contribute to heterogenicity to a lesser extent. A large spatial variation in bacterial populations was observed over short distances ( approximately 1 m) in sampling areas within the same site. These analyses show that the culturable bacterial distribution in sediments of mangroves has high spatial and temporal heterogeneity.