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Abstract.Lipase is an enzyme that is often used in industry and become a commercial enzyme. One group of microorganisms capable of producing lipase is a yeast. This study aims to screen yeast from Wonorejo mangrove that potential to produce lipase and to optimize the production of these enzymes. Screening test include the measurement of lipolytic index and value of fatty acid. Yeast with the best value of fatty acid will be continued to the measurement of lipase activity. It is affected by several environmental factors, such as pH, temperature, and incubation time. This research was conducted to observe the optimization variation on environmental factors combination to produce lipase. Lipase activity was tested by using p-Nitrophenyl Palmitate (pNPP). Absorbency was measured by spectrofotometer on wavelength of 410 nm. Measurement of the enzyme activity was done by interpolating the absorbance values on the p-nitrophenol standard curve then calculated by the formula. All data were analyzed by using descriptive quantitative method. The results show that the highest lypolityc index was 2.08. The highest value of fatty acid was 0.49 that was reached on 168 hours of incubation. Candida W3.8 expressed the highest lypolylitic potential. The optimum environment to produce lipase by Candida W 3.8 was on 120 hours of incubation time, in temperature range of 27 C -45 C and pH range of 4,5 -7.

Abstract. Kuswytasari ND, Kurniawati AR, Alami NH, Zulaika E, Shovitri M, Oh KM, Puspaningsih TP, Ni’matuzahroh. 2019. Plastic degradation by Coriolopsis byrsina, an identified white-rot, soil-borne mangrove fungal isolate from Surabaya, East Java, Indonesia. Biodiversitas 20: 867-871. The work deals with an important environmental issue, the disposal of plastic waste. The degradation of plastic by white-rot fungi of soil-borne mangrove isolate, T1P2, from Surabaya, East Java, Indonesia, was investigated using Minimal Salt Medium and the ability of the degradation was indicated as the amount of degradation efficiency. Analysis of the 18S rDNA sequence successfully identified the ligninolitic fungal isolated, T1P2, as Coriolopsis byrsina. The results have been revealed that C. byrsina have more potential to degrade plastic with maximum % DE was 22,7% for six weeks compared with the enzymatic plastic degradation reached 6,3% for two days. However, this study needs to do further investigation of extracellular enzyme that involved in degradation process.

Abstract. Zulaika E, Utomo MAP, Alami NH, Kuswytasari ND, Shovitri M, Bayuaji R, Prasetyo EN. 2019. Short communication: The diversity of ureolytic bacteria isolated from limestone in East Java, Indonesia based on amino acid sequences encoded by ureC. Biodiversitas 20: 2316-2320. Ureolytic bacteria isolated from limestone are capable to produce urease enzyme which can breaks down urea into carbonate (CO32), has been utilized for various building material bioremediation and restoration. In this present study, we figured out the diversity and genetic relationship of α sub-unit ureC gene among six ureolytic bacteria (JA1, JB2, JB3, JA4, AK4, and SU1) which were isolated from limestone area in East Java province. PCR was conducted to detect the gene which encoded active site of urease, ureC. Followed by sequences translation using BLAST-X (Basic Local Alignment Search Tool) based on the name and function of formed proteins and then aligned to the conserved domain database. Furthermore, the functions and characters of formed proteins were described. Based on PCR results, all isolates showed 340 bp DNA band which indicate the presence of ureC gene. The results of BLAST-X, JB2 isolates showed 100% similarity with the α sub-unit ureC gene from Lysinibacillus sphaericus B1-CDA (WP_054549252.1). Whereas, JA1 isolates showed 88% similarity (lowest) with the α sub-unit ureC gene from Bacillus cihuensis FJAT-14515 (WP_028391929.1). The present study reveals that ureC phylogeny can be used in order to investigate ureolytic bacteria species which isolated from calcareous area in East Java province.

Study to determine the antibacterial activity of wet and dry extract of the leaf, fruit, and bark of Calabash tree (Crescentia cujete L.) against the growth of Aeromonas hydrophila. The solvent extraction process was done by using 96% ethanol in the maceration method. Antibacterial test results using diffusion agar to decide clear zone and tube series of dilution test to provide MIC and MBC. Fresh leaf extract produces the highest clear zone diameter (20.06 mm), after which fresh bark extract (12.81 mm), and the last is fresh fruit extract (3.22 mm). In contrast to fresh extracts, the dried extracts are have not clear zone. MIC (Minimum Inhibitory Concentration) of Calabash Tree fresh leaf extract against Aeromonas hydrophila is 80%, and MBC (Minimum Bactericidal Concentration) is 100%.