Production and Evaluation of Biosurfactant by Serratia marcescens UCP 1549 Using Industrial Wastes.

Aims: Biosurfactants are surface-active agents of microbial origin that have a property of lowering the surface tension between two liquids. This study aimed to the production of biosurfactant by Serratia marcescens UCP 1549 in medium containing agro-industrial wastes for making possible its industrial application in the near future and to propose its environmental applications. Place and Duration of Study: Center of Science and Technology from State University of Paraíba - UEPB, Campina Grande – PB, Brazil and Nucleus of Research in Environmental Sciences and Biotechnology (NPCIAMB), Catholic University of Pernambuco - UNICAP, Recife-PE, Brazil between June 2011 and July 2012. Methodology: According to the proposed factorial design, the culture medium was developed and used for the production of biosurfactant and incubated at 28ºC, 155 rpm during 48 h. The produced biosurfactant was evaluated by emulsifying index, emulsifying activity and surface tension using hydrophobic substrates as vegetable oils after frying, nhexadecane and diesel. Results: The best results for emulsification index were found between 79.92 and 100% of emulsification and for activity were values between 2.304 and 5.000 EA (emulsification activity) using vegetable oil after frying as substrate. In relation of the surface tension, the best value obtained was 33.10mN/m in the condition of the central point of the experimental design. Conclusion: The results show that Serratia marcescens UCP 1549 was capable of producing a biosurfactant with emulsifying property from industrial wastes in the studied conditions in this work.

Aspectos da biologia reprodutiva da corvina Pachyurus squamipinnis Agassiz, 1829 (Teleostei, Sciaenidae) na Represa de Três Marias, MG / Reproductive biological aspects of the corvina Pachyurus squamipinnis Agassiz, 1829 (Teleostei, Sciaenidae) in the Tres Marias reservoir, MG, Brazil

Gônadas de 599 exemplares de P. squamipinnis, capturados na represa de Três Marias no período de julho/85 a junho/86, foram analisadas por métodos histológicos. A maioria dos peixes encontravam-se em repouso. Machos em maturaçäo foram observados durante todo o ano. Somente nove fêmeas em maturaçäo avançada foram registradas e fêmeas desovadas näo foram capturadas. Entretanto, há indicaçöes de que a espécie completa seu ciclo reprodutivo na represa. O tamanho de primeira maturaçäo sexual (L50) de fêmeas foi estimado em 21,4cm de comprimento padräo (CP). Todas as fêmeas estäo aptas a reproduzirem-se (L100) a partir de 26,5cm CP