The venomous Levantine viper, Macrovipera lebetina lebetina is endemic to Cyprus. The objective of this study was to investigate in vitro cytotoxicity, in vivo lethality, and antivenom production followed by a re-immunization schedule in mice against Macrovipera lebetina lebetina venom. The LD50 value was estimated as 7.58 mg/kg within 24 hours by different venom doses administrated intraperitoneally in mice. Freund's complete and incomplete adjuvants were used for first and second immunization of mice in antivenom production. A cell-based assay was performed to determine the effects of Macrovipera lebetina lebetina venom and antivenom neutralizing potency on L929 cell viability. The snake venom toxicity and cytotoxicity were examined and comparison of results showed good correlation, the LD50 value was tenfold higher than the IC50 value. The IC50 value was 0.62 ± 0.18 mL after 48 hours treatment while the calculated value was 1.62 ± 0.25 mL for the culture media totally refreshed after two hours treatment with venom. The in vitro efficacy of antivenom against Macrovipera lebetina lebetina venom was found to be low. This is the first report that describes the in vivo and in vitro toxic effects of Macrovipera lebetina lebetina venom and antivenom production against this species.

Bacillus sp AB68 alcalifílico produtor de α-amilase alcalina termoestável foi isolado do lago Van soda. A síntese da enzima ocorreu entre 25ºC e 40ºC. A análise da enzima por SDS-PAGE revelou uma única banda estimada em 66 kDa. A enzima foi ativa em uma ampla faixa de temperatura, entre 20ºC e 90ºC, com um ótimo a 50ºC. A atividade máxima foi em pH 10,5. A enzima foi estável até 80ºC, mantendo 90% de atividade após 30 min de pré-incubação. A termoestabilidade não aumentou na presença de Ca2+. Quando incubada em pH entre 5 e 9 por 1h e por 2h, a enzima manteve 75% e 60% de atividade, respectivamente. SDS e EDTA causaram redução de 38% e 34% na atividade da enzima, respectivamente.

An alkaliphilic and highly thermostable α-amylase producing Bacillus sp. was isolated from Van soda lake. Enzyme synthesis occurred at temperatures between 25ºC and 40ºC. Analysis of the enzyme by SDS-PAGE revealed a single band which was estimated to be 66 kDa. The enzyme was active in a broad temperature range, between 20ºC and 90ºC, with an optimum at 50ºC; and maximum activity was at pH 10.5. The enzyme was almost completely stable up to 80ºC with a remaining activity over 90% after 30 min pre-incubation. Thermostability was not increased in the presence of Ca2+. An average of 75% and 60ºC of remaining activity was observed when the enzyme was incubated between pH 5 and 9 for 1 h and for 2 h, respectively. The activity of the enzyme was inhibited by SDS and EDTA by 38% and 34%, respectively.