Abstract Marine toxicity tests using sea urchin embryos and larvae are characterized by physicochemical induction for the release of gametes by adult organisms and by the production of excess gamic material after induction. Evaluating the effects of mortality that inducers cause on organisms, and the improvement in oocyte maintenance techniques for subsequent use, are actions of interest in the conservation of species and the sustainable use of this type of biological model. For this study, adults of the sea urchin species Lytechinus variegatus and Echinometra lucunter were obtained from the field for inductions and tests with their gametes in the laboratory. The species L. variegatus was used in maintenance experiments to assess health after induction (longline outdoor and indoor tanks) and mortality rates after induction by potassium chloride (KCl) and a mixture of potassium chloride with calcium chloride (CaCl2), and to evaluate bacterial growth as well as antibiograms of seawater resulting from induced spawning and in vitro fertilization. For the species E. lucunter, experiments with the same chemical inducers on mortality rates were carried out, as well as the conservation of oocytes in artificial seawater with antibiotics selected for their efficiency and toxicity for later use. Maintenance in the laboratory tanks, filled with seawater in a closed system, showed the lowest mortality rates in the group of non-induced organisms (control). The mixture of KCl and CaCl2 resulted in the lowest mortality rates of the adult organisms after spawning induction. The antibiotics Chloramphenicol and Gentamicin showed moderate efficiency in inhibiting bacterial growth, but with low toxicity, demonstrating the ability to maintain the integrity of sea urchin oocytes for up to 14 days under refrigeration.

Abstract Bacteria with lipolytic activity are widespread in the marine environment. These organisms can be used as a source of lipases with activity in unusual conditions such as low temperatures and high salinities. These characteristics allow them to be applied to several industrial processes and products including wastewater treatment and detergent production. In this context the lipolytic activity of bacteria isolated from deep-sea sediments of the South Atlantic was evaluated. Among the collection studied, two strains, Halomonas sulfidaeris LAMA 838 and Marinobacter excellens LAMA 842, were selected for further analysis concerning their growth and lipolytic activity in different temperatures and culture media. Both strains were characterized as mesophiles: H. sulfidaeris LAMA 838 grew best at 30ºC, while M. excellens LAMA 842 showed a maximum growth rate between 20 and 25ºC. Maximum lipolytic activity for both microorganisms was observed above 45ºC, but only M. excellens LAMA 842 had lipolytic activity at low temperatures (5ºC) as well. Considering the culture media employed, H. sulfidaeris LAMA 838 grew better in marine broth without Tween 40, while M. excellens LAMA 842 grew best in marine broth supplemented with Tween 40. Both organisms had maximum lipolytic activity in rich or minimal media supplemented with Tween 40. These results demonstrate the potential of deep-sea bacteria as sources of lipases and indicate conditions that may be used in their cultivation and for the production of industrially relevant enzymes.

Background: Cellulases and lipases have broad industrial application, which calls for an urgent exploration of microorganisms from extreme environments as valuable source of commercial enzyme. In this context, the present work describes the bioprospection and identification of deep-sea bacteria that produce cellulases and lipases, as well their optimal temperature of activity. Results: The first step of this study was the screening of cellulolytic and lipolytic deep-sea bacteria from sediment and water column, which was conducted with substrates linked with 4-Methylumbelliferyl. Among the 161 strains evaluated, 40 were cellulolytic, 23 were lipolytic and 5 exhibited both activities. Cellulolytic and lipolytic bacteria are more common in sediment than at the water column. Based on the ability to produce cellulases and lipases three isolates were selected and identified (16S rRNA sequencing) as Bacillus stratosphericus, B. aerophilus and B. pumilus. Lipases of strain B. aerophilus LAMA 582 exhibited activity at a wide temperature range (4º to 37ºC) and include psychrophilic behaviour. Strain Bacillus stratosphericus LAMA 585 can growth in a rich (Luria Bertani) and minimal (Marine Minimal) medium, and does not need an inducer to produce its mesophilic cellulases and lipases. Conclusions: Deep-sea sediments have great potential for bioprospection of cellulase and lipase-producing bacteria. The strains LAMA 582 and LAMA 585 with their special features, exhibit a great potential to application at many biotechnology process.

Bactérias ácido-láticas (BAL) constituem um grupo diverso, associado à produção de alimentos, incluindo fermentados de peixe. Por meio de processos fermentativos, é possível obter produtos mais saborosos e saudáveis. Estas bactérias também são importantes na medicina por suas atividades probióticas. Neste contexto, nove linhagens de bactérias ácido-láticas foram isoladas de sardinha e guaivira. Destas, duas linhagens foram caracterizadas fisiologicamente, juntamente com Leuconostoc mesenteroides ATCC8293. Lactobacillus homohiochii F3 apresentou ótimo crescimento a 40 ºC, diferente de Lactobacillus intestinalis G1 e Leuconostoc mesenteroides ATCC8293, que tiveram ótimo crescimento a 30 ºC. Em relação à tolerância ao NaCl, L. homohiochii F3 e L. mesenteroides ATCC8293 toleraram uma concentração de 5% de NaCl no meio. A espécie L. intestinalis G1 tolerou uma concentração de 7,5%, podendo ser considerada mais halotolerante que as demais espécies. L. mesenteroides ATCC8293, por causa do aumento da taxa de crescimento, pode ser considerada levemente halofílica. Na presença de concentrações não ótimas de NaCl, a adição de solutos orgânicos foi eficaz na restauração do balanço osmótico das células

Lactic acid bacteria constitute a diversified group associated with the production of food, including fermented fishes. Through fermentative processes, it is possible to obtain several healthy and tasty products. Those bacteria are also important in medicine due to their probiotic activities. In this context, nine lactic acid bacteria were isolated from sardine and leatherjacket fish. Among them, two lineages, and the reference strain Leuconostoc mesenteroides ATCC8293 were physiologically characterized. Lactobacillus homohiochii F3 grew optimally at 40 ºC, differently from Lactobacillus intestinalis G1 and Leuconostoc mesenteroides ATCC8293 that grew optimally at 30 ºC. With regard to NaCl tolerance, L. homohiochii F3 and L. mesenteroides ATCC8293 grew in media containing 5% NaCl. Lactobacillus intestinalis G1 grew in media containing 7.5% NaCl and can be considered more halotolerant than the other species. L. mesenteroides ATCC8293 can be considered slightly halophilic. In non-optimal NaCl concentrations, the addition of organic solutes to the culture media was effective in restoring the osmotic balance of the bacteria