Abstract. Sarkono, Faturrahman, Sofyan Y. 2010. Isolation and identification of lactic acid bacteria from abalone (Haliotis asinina) as a potential candidate of probiotic. Nusantara Bioscience 2: 38-42. The purpose of this study was to isolate, select and characterize lactic acid bacteria (LAB) from abalone as a potential candidate probiotic in abalone cultivation system. Selective isolation of LAB performed using de Man Rogosa Sharpe medium. LAB isolate that potential as probiotics were screened. Selection was based on its ability to suppress the growth of pathogenic bacteria, bacterial resistance to acidic conditions and bacterial resistance to bile salts (bile). Further characterization and identification conducted to determine the species. The results showed that two of the ten isolates potential to be developed as probiotic bacteria that have the ability to inhibit several pathogenic bacteria such as Escherichia coli, Bacillus cereus dan Staphylococcus aureus, able to grow at acidic condition and bile tolerance during the incubation for 24 hours. Based on the API test kit, both isolate identified as members of the species Lactobacillus paracasei ssp. paracasei.

Eugenol and its new or known derivatives were prepared through varies reactions and screened by in vitro model of antibacterial activities using pathogen bacteria: Eschericia coli, Bacillus cereus, and Staphylococcus aureus. Nearly all compounds showed antibacterial activities. The obtained results demonstrate that eugenol was still significantly more active than its derivatives, with inhibition (14-18) mm, suggesting that this chemical transformation failed to increase antibacterial activities of eugenol. The presence of nitro, cyclic sulfonic ester, N-dimethyl, quinoline, amino, isocyanate, amide and ester moieties has no ability to enhance the antibacterial activities of eugenol.

Physicochemical properties of bacterial cellulose produced by newly acetic acid bacterial strain Gluconacetobacter xylinus ANG-29 in different fermentation methods were compared using SEM and XRD techniques. Production of cellulose by G. xylinus ANG-29 with static fermentation method, shaking at 50 rpm, 100 rpm and 150 rpm were 1.59±0.08 g/100 ml, 0.17±0.02 g/100 ml, 0.11±0.00 g/100 ml and 0.21±0.01 g/100 ml, respectively. The degree of crystallinity determined by XRD method in static fermentation was 93%, shaking fermentation at100 rpm was 51% and shaking fermentation at150 rpm was 65%. Static fermentation method produced bacterial cellulose in the sheets form, while shaking fermentation produced fragmented cellulose with predominantly spherical shape. The observation of surface structure of bacterial cellulose by SEM showed that the static fermentation method generated woven densely of cellulose microfibrils. Shaking fermentation caused the woven microfibrils become more loose and formed a larger holes. Bacterial cellulose produced from both fermentation methods had their own advantages depending on the application.

Bacillus thuringiensis is bacteria utilised to control Aedes aegypti larvae for many years. However, there is no B. thuringiensis commercial products are commercially available in Indonesia. Therefore, development of B. thuringiensis-based biolarvicide using indigenous strain and local medium is very important. The aim of the study were to evaluate growth and toxicity of Mataram indigenous Bacillus thuringiensis isolate when grown on coconut milk and cane sugar as natural culture. Mataram indigenous B. thuringiensis isolate (namely Bt-TP2B) was grown in liquid medium consisted of coconut milk and cane sugar in 4 ratios (1:1; 1:3; 1:5 and 1:7) for 7x24 hours. Cell, endospore, and parasporal crystal (toxin protein) concentration were measured every 24 hours for 7x24 hours. Toxicity of the cultures was evaluated against 3rd instar of A. aegypti larvae. This study showed that the highest cell, endospore and toxin protein crystal concentration was shown by B. thuringiensis grown in ratio of 1:7, which were 2.20x107 cell/mL, 2.09x107 endospore/mL and 9.85x106 crystal/mL, repectively. The highest toxicity against 3rd instar A. aegypti larvae was shown by B. thuringiensis grown in ratio of 1:7 which was 90-100% (in 3-day observation). From this study It was concluded that natural medium consisted of coconut milk and cane sugar can be used to grow B. thuringiensis and to stimulate toxicity against 3rd instar of A. aegypti larvae.