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One of the benefits of probiotic bacteria is to become a source of protein that can be used as a product in the field of biotechnology with high use value. Proteins derived from bacteria are less widely used compared to animals and fungi. The aim of this study is to analyze the composition of the media and the optimal time for the growth of a consortium of Bacillus cereus bacteria. The experimental method used is a consortium of B. cereus bacteria isolates (5 Strains) six treatments in each B. cereus consortium, namely the addition of a different protein source (eggs and skim milk, the same carbohydrate source, namely Sago) and 3 different concentrations in each protein source (8%, 10%, and 12%) so that the treatment obtained was 6 treatments with 3 replications in each treatment. Measurement of bacterial culture growth was carried out every 6 hours for 24 hours using two methods, namely the TPC method and bacterial cell biomass. Optimal growth was found in sago media which was added in different concentrations, namely 12% due to growth in this medium which was close to the same results as growth in positive control. Growth on biomass measurements showed similar results to the growth pattern similar to TPC. While in milk sago media, the growth is less because the exponential and stationary phases are shorter.

Protein is the main source of nutrition in fish feed. It is necessary to use bacterial single-cell protein (SCPs) as a substitute for conventional protein. This study aims to determine the effectiveness of tofu liquid waste as a growth medium for biomass production of Bacillus cereus as an SCPs. The isolates used were B. cereus SN7 and B. cereus consortium (combination of 5 isolates of B. cereus with different strains). The method used was experimental where isolates were cultured in a medium containing tofu liquid waste with different concentrations (8%, 10%, and 12%) enriched with 10% skim milk. Furthermore, the analysis of an effective growth medium was carried out by three methods, namely total plate count, optical density, and cell-dry weight. Cell biomass measurements were carried out for 24 hours with an observation time of every 6 hours. The results showed the best growth medium used in the culture of B. cereus SN7 and B. cereus consortium was tofu liquid waste at a concentration of 12% enriched with 10% skim milk. In conclusion, the cell mass of B. cereus SN7 and B. cereus consortium significantly increased at 6 to 12 hours.

Dumai is one of the coastal waters of Indonesia that has the potential for the biodiversity of microorganisms including anoxygenic photosynthetic bacteria (APB). Anoxygenic photosynthetic bacteria are bacteria that carry out decomposition activities even though oxygen levels in water and sediment are very little or even absent. This study aims to determine anoxygenic photosynthetic bacteria from aquatic and sedimentary ecosystems in the coastal waters of Dumai, Indonesia. This research was conducted by an experimental method using modified mineral media. The APB was isolated from six different places in sequence, namely Dumai sea station, river prayer room, harbor, shrimp pond area, fish auction place, and, Purnama tour. All bacteria obtained were then characterized by their morphological and physiological characteristics. The isolation results showed that 15 different bacterial isolates were obtained after being determined based on Bergey’s Manual of Determinative Bacteriology. All isolates contained different pigments such as carotenoids, xanthophylls, and, chlorophylls. Thus, further utilization of APB bacteria can be carried out in various microbiological applications such as bioremediation, aquaculture, biofuel, food, and medicines.

Peatlands are terrestrial wetland ecosystems formed from piles of organic matter that decompose into organic deposits. Peat soil has a high potential to produce cellulose which, can be reused by cellulolytic bacteria. This study aims to find out the potential strain of cellulolytic bacteria isolated from peatland ecosystems. The method used was experimental, sequentially, the stages are isolation and screening for cellulolytic bacteria, quantitative testing of cellulolytic activity, characterizing the morphology and physiology of bacteria, and the identification of bacteria based on Bergey’s Manual of Determinative Bacteriology. The screening results obtained seven isolates of cellulolytic bacteria capable of hydrolysed cellulose on 1% Carboxy Methyl Cellulose (CMC) Agar Medium, namely SPS1, SPS2, SPS 3, SDG1, SDG 2, SPW1, and SPW4. Three of seven isolates obtained the highest cellulolytic index sequentially, namely SPS2 of 2.82, SPS3 of 2.65, and SDG1 of 2.47. The cellulolytic activity was indicated by the value of a halo zone around the colonies on 1 % CMC medium after being dripped with Congo red. The halo zone is an early indication to determine the ability of bacteria to decompose cellulose. Based on Bergey’s Manual of Determinative Bacteriology showed that the three isolates had the same characteristics as the genus Bacillus, Lactobacillus and Corynebacterium.

The mangrove ecosystem is a coastal wetland resource that has a diversity of biodiversities such as flora, fauna, and microorganisms. Microbes are an important component in the mangrove environment not only play a role in creating and maintaining boosters but also work as a source of biotechnology products. Cellulolytic bacteria are a group of cellulase-producing bacteria capable of breaking down cellulose into glucose monomers, and cellulose as a source of carbon and energy. This study aims to screen and determine the diversity of cellulolytic bacteria from the mangrove ecosystem. The research method was experimentally by exploring the diversity of cellulolytic bacteria from soil and sediment from the mangrove ecosystem. Three sampling locations were selected, such as litter soil, soil in the root area, and soil in the tidal area. Screening of potential bacteria producing cellulase enzymes was carried out by growing bacteria on Carboxy Methyl Cellulose (CMC) agar medium which was cultured for 48 hours at 37°C. The bacteria that produced the greatest cellulolytic activity were characterized by their morphological and physiological characteristics. The results of bacterial characterization were then adjusted according to Bergey's Manual of Determinative Bacteriology. Based on the analysis showed three bacterial isolates were obtained that had the largest cellulolytic activity index, namely MS06 (9.73), MS08 (5.41), and MS02 (5.07). The results showed that three isolates had the same characteristics as the bacterial genera Bacillus, Cellulomonas, and Micrococcus.

The presence of pathogenic bacteria in shrimp culture water could influence the shrimp growth and production. This research aimed to quantify total coliform, Escherichia coli and total Vibrio in pond water of Vannamei shrimp (Litopenaeus vannamei) culture in Rupat Island. Water samples from inlet water (IW), water from three ponds (PW2, PW3, PW6) and outlet water (OW) were collected for the quantification of total coliform and Escherichia coli by the MPN technique and total Vibrio count on TCBS agar. Coliforms was found in all water samples, the lowest count was in inlet water sample (20 MPN/100 mL), and the highest was contained in outlet water (>2400 MPN/100 mL), however E. coli was not detected in all water samples. Meanwhile, the lowest total Vibrio count was found in PW3 (6.35 × 103), and the highest was in the PW6 (3.10 × 105). In addition to the microbiological quality, some water quality parameters were also observed, those were water temperature in the range of 27.5- 29.4°C, salinity of 18.7-21.5 ppt, pH of 7.17-7.89, DO of 1.3-7.6 mg/L, NH3 content of 0.96-1.26 mg/L and DOM of 26.2–27.6 mg/L. The data indicated that pathogenic bacteria were present in all pond waters which should be decreased for the safety shrimp production.

Palm liquid sewage is organic waste that contains complex compounds such as water, oil, and organic solids. The organic content of palm liquid sewages is an indication of the abundance of microorganisms. This study aims to obtain anoxygenic photosynthetic bacteria (BFA) that produce carotenoid pigments from palm liquid sewages. Therefore, We isolated and screened of BFA from three palm liquid sewage disposal sites in Jambi Province. This research was conducted by an experimental method using a modified mineral medium. BFA isolates that growth and produced carotenoid pigments are visible because of the distribution of reddish-yellow pigments on the culture media. Screening results obtained 11 isolates of BFA sequentially Bg1K201, Bg1K202, Bg2k201, Bg3k201, Mr1k201, Mr1k202, Sl1k201, Sl1k202, Sl2k201, Sl2k202 and Sl3k202. The results of morphological and physiological characterization based on the Bergeys Manual of Determinative Bacteriology show that there are two types of BFA genera that have carotenoid pigments, respectively, the genus Rhodobacter (Bg1k201, Bg1k202, Bg3k201, Sl1k201, Sl1k202, and Sl1k202, and Sl2k202, and Sl1k202, and Sl2k202, and Sl1k202 and Sl2k202, and Sl2k202, and Sl2k202. Sl2k202, and) the genus Rhodopseudomonas (Bg2k201, Mr1k201 and Mr1k202)