Exopolysaccharides-Producing Biofilm Bacteria from Submerged Seawater Substrate for Bioremediation of Heavy Metal Contamination.

<b>Background and Objective:</b> The coastal environment is often polluted by various toxic compounds such as heavy metals. Exposure to these toxic compounds causes coastal bacteria to adapt so that they can be used as bioremediation agents for heavy metals. This study aims for finding and screening the ability of bacteria to produce exopolysaccharide biofilms and then determine the characteristics of bacterial isolates as agents candidates for heavy metal bioremediation in the coastal environment. <b>Materials and Methods:</b> Samples were collected on submerged seawater substrate from Bungus Coastal, Padang and West Sumatra, on the wet area that was exposed by seawater (on the rocks, on the wood and the ship, the lower out part on the ship that exposed to seawater). Bacterial isolation process using Marine Agar Medium. The isolate discovered then observed and purified. Furthermore, Congo Red Agar was used for bacteria screening for detecting EPS produced by biofilm bacteria. <b>Results:</b> The results of the isolation, found 9 bacterial isolates attached to the substrate submerged seawater. The screening results showed that isolates K4, K5 and K7 were positive as biofilm-forming bacteria as indicated by the colour change of the bacterial colonies to black on Congo Red Media after 24 hrs incubation. The characteristics of the three bacterial isolates were gram-negative, with cocci and bacilli cells form. <b>Conclusion:</b> Three isolates of positive exopolysaccharide biofilm bacteria that 1 isolate gram-negative coccus (K4) and the other 2 isolates (K5 and K7) were bacillus. Then, the 3 isolates can be used for remediation of metal contamination research in aquatic.

Enzyme Activity of Cellulolytic Bacteria from Biological Education and Research Forest Floor Andalas University.

<b>Background and Objective:</b> The composition of the waste consists mostly of plant biomass. Cellulose is the largest component of plant biomass and cellulolytic bacteria are needed to degrade it. This study aimed to determine enzyme activity possessed by bacterial isolates from Biological Education and Research Forest floor Andalas University. <b>Materials and Methods:</b> The isolation stage was carried out with NA (Nutrient agar) medium, Screening with CMC (Carboxymethyl Cellulose) medium with congo red dye and enzyme activity testing was carried out using the Nelson-Somogyi method. <b>Results:</b> We found 16 bacterial isolates obtained from Biological Education and Research Forest Floor Andalas University, 10 of them were positive for cellulolytic bacteria with the highest cellulolytic index value of 2.59 on FFB 2 isolates. <b>Conclusion:</b> The bacterial isolate with the best enzyme activity value was FFB 2 isolate 0.166 U mL¹ for 72 hrs.

Screening of Cellulolytic Bacteria from Biological Education and Research Forest Floor Andalas University, Indonesia.

<b>Background and Objective:</b> Organic waste dump is a problem that needs to be solved, one of which is by using microbe. Cellulolytic bacteria's ability to produce cellulase enzymes that can hydrolyze cellulose. Cellulose is the major component of the plant cell walls that are difficult to endure degradation naturally. This study aimed to find cellulolytic bacterial isolates on Biological Education and Research Forest floor Andalas University and characterize the cellulolytic bacteria found. Material and Methods: CMC (Carboxymethyl Cellulose) medium is used as a screening for bacteria isolate and this study used the survey method and also conducted catalase, glucose and lactose test for characterizations. <b>Results:</b> We found 16 bacterial isolates on Biological Education and Research Forest floor where 9 isolates were in a shaded area and 7 isolates were in an unshaded area. There were 12 isolates from 16 isolates that have the positive cellulolytic ability with a variety of clear zone sizes, where there were 8 isolates with the large clear zone and 4 isolates producing very small clear zones. Characteristics of bacterial isolates with the large clear zone obtained were 2 gram-positive coccus isolates with positive catalase test, 3 gram-negative coccus isolates with positive glucose test and 3 gram-negative bacilli isolates with negative fructose test. <b>Conclusion:</b> We identified 2 potential isolates with a cellulolytic index value greater than 2, isolate UCB 4 with a cellulolytic index value of 3.5 and UCB 6 with a cellulolytic index value of 2.2.

Isolation, Screening and Characterization of Ureolytic Bacteria from Cave Ornament.

<b>Background and Objective:</b> Ureolytic bacteria are bacteria capable of hydrolyzing urea. In construction, these bacteria are known to help improve soil stability. One of the habitats of ureolytic bacteria is cave ornaments such as gourdam, flowstone, stalagmite and stalactite. This study aims to find isolates and characterization of ureolytic bacteria in cave ornaments. <b>Materials and Methods:</b> Urea-CaCl₂ was used as the isolation medium and urea agar medium was used as a qualitative urease test for cave ornament bacteria isolate. This study applied a survey method and tested for gram staining, spore staining, mannitol test, catalase test and lactose test for characterization. <b>Results:</b> There were 17 isolates positive for urease from 30 isolates from the isolates of cave ornament bacteria. The characteristics of 17 ureolytic bacteria isolates were 2 isolates gram-negative basil with negative lactose test and 1 isolate positive glucose and 1 isolate negative glucose. Total 15 isolates gram-positive basil with spore staining results, 14 isolates spore-positive with 2 isolates positive mannitol and 12 isolates negative mannitol and 1 isolate spore-negative with negative catalase. <b>Conclusion:</b> Total 17 ureolytic bacteria isolates were found from cave ornaments. Biochemical characterization showed 1 isolate of <i>Proteus</i> spp., 1 isolate of <i>Pseudomonas</i> spp, 2 isolates suspected of being <i>Bacillus megaterium</i> or <i>Bacillus subtilis</i>, 12 isolates of <i>Bacillus cereus</i> and 1 isolate of <i>Lactobacillus</i> spp.