Prevalence of Nosema ceranae in apiculture regions of Bahia state, Brazil / Prevalência de Nosema ceranae em regiões apícolas do estado da Bahia, Brasil

Nosemosis is an important bee disease that is caused by microsporidia fungi of the Nosema genus, whose main etiological agents are Nosema apis and N. ceranae, both of which are found worldwide. In Brazil, the disease has been reported in several states but little is known about its occurrence and distribution in Bahia. This study identified the occurrence and distribution of nosemosis and its agents, N. apis and N. ceranae, in Apis mellifera L. bees collected from apiaries in the state of Bahia, Brazil. A total of 154 bee samples were collected and analyzed from 20 apiaries in six regions of the state. The hives sampled were evaluated for signs of the disease from December 2015 to July 2018. Molecular diagnosis was made using polymerase chain reaction (PCR). No signs of nosemosis were observed in the sampled apiaries, but from 154 samples analyzed via PCR, 96 were infected with N. ceranae. This pathogen was reported in samples from all six regions evaluated, and its occurrence in important apiculture regions of Bahia State is discussed in this study.

A nosemose é uma importante doença das abelhas, sendo ocasionada por fungos microsporídios do gênero Nosema. Os principais agentes etiológicos desta doença são Nosema apis e N. ceranae, ambos bem difundidos mundialmente. No Brasil, a doença possui relatos em diversos estados, entretanto, pouco se sabe sobre sua ocorrência e distribuição na Bahia. O objetivo deste estudo foi identificar a ocorrência e distribuição da nosemose e de seus agentes, N. apis e N. ceranae, em abelhas Apis mellifera L. coletadas em apiários do estado da Bahia, Brasil. Foram analisadas 154 amostras de abelhas coletadas em 20 apiários de seis regiões apícolas do Estado. As colmeias amostradas foram avaliadas quanto aos sinais da doença no período de dezembro de 2015 a julho de 2018. O diagnóstico molecular foi realizado via reação em cadeia da polimerase (PCR). Não foram observados sinais da nosemose nos apiários amostrados e, das 154 amostras analisadas via PCR, 96 estavam infectadas por N. ceranae e N. apis não foi detectada. O patógeno N. ceranae foi encontrado em amostras das seis regiões avaliadas. A distribuição de N. ceranae em importantes regiões apícolas do estado da Bahia é discutida neste artigo.

Biotechnological Assessment of Culture Conditions on the Stress-Induced Carotenoid Production of Dunaliella salina and Growth Kinetics of Chlorophyceae Microalgae Strains

Abstract Microalgae are potential sources of a wide range of bioproducts. It is essential to choose the proper microalgae strain and culture condition to achieve an efficient production. The production yield of carotenoids by Dunaliella salina under the stress-induced culture conditions of nitrogen deprivation and excessive light intensity was evaluated. Also, a survey at laboratorial scale of the growth kinetics under different culture conditions of photoperiod, aeration, and agitation was performed for the seven species of green microalgae Ankistrodesmus fusiformis, Chlamydocapsa bacillus, Desmodesmus brasiliensis, Kirchneriella lunaris, Pseudokirchneriella subcapitata, and Scenedesmus obliquus. As a result, aeration of atmospheric air is enough to improve the growth kinetics of the seven species studied. Production of carotenoids was enhanced under stress by excessive light intensity. Although D. salina does not grow effectively under nitrogen deprivation, this stress condition may be used to quickly stimulate carotenoid production once the culture reaches a high cellular population.