Exploration of IAA Producing Bacteria And Amylolitic Bacteria From Several East Java Lakes, and Their Potency For Microbial Consortium To Accelerate Chlorella Vulgaris Growth

Abstract

The consortium of various types of bacteria from lakes in East Java has the potency to stimulate microalgae Chlorella vulgaris growth. Increased microalgae density from co-culture has an excellent potency for sources of biomass that can be developed for renewable energy. Several stages conducted of this research started from an exploration of IAA producing bacteria and amylolytic bacteria from several East Java Lakes; then, the highest bacterial isolates were identified with morphological and genotypical characteristics. The well-characterized bacterial isolates were used for the microbial consortium in co-culture with C. vulgaris. The treatment used in this study as follows: I) C. vulgaris without bacteria culture as a control, II) amylolytic bacteria + C. vulgaris, III) IAA-producing bacteria + C. vulgaris, IV) potential amylolytic bacteria and IAA-producing bacteria + C. vulgaris. The exploration result of potential bacteria from Ranu Pani, Ranu Regulo, Telaga Ngebel, and Ranu Grati lakes was found 53 amylolytic bacterial isolates, and 90 isolates IAA-producing bacteria. The highest amylolytic bacteria (isolate L) is related to Bacillus amyloliquefaciens, while the most elevated IAA-producing bacteria (isolate C) is related to Bacillus paramycoides. The highest cell density was produced in treatment III, reaching 2.7 x 106 cells/mL on day 50th. The treatments with supplement bacteria showed a significant effect for accelerating the growth of microalgae compared to control.

Isolation and characterization of α ‐amylase encoding gene in Bacillus amyloliquefaciens PAS

“…The αamylase sequence charac terization from this bacterial isolate is important for fur ther study, especially for their application to enhance the microalgae biomass in the mini bioreactor (Fuentes et al 2016; Han et al 2016 and to produce αamylase recombi Rodiansyah et al Indonesian Journal of Biotechnology 26(4), 2021, 166-174 nant (Niu et al 2009). In our study, the culture of Chlorella vulgaris with the coculture method in the mini bioreactor containing modifiedGusrina medium combined with PAS bacterial culture had proved to improve microalgae growth and biomass production (Nafi'ah et al 2021).…”

“…Moreover, the biochemical characterization of that bacterial isolate also showed the similar characteris tics with B. substilis, reaching 66% identity. Bacterial iso late PAS could reduce the complex sugar about of 27,391 ppm with the enzyme activity of 0.01 units/mL (Nisa et al 2021) and the amylum hydrolysis index of that isolate was about of 5.9 (Nafi'ah et al 2021). Based on that result, the amylolytic activity of PAS bacterial isolate was relatively high.…”