Ardhi A, Sidauruk AN, Suraya N, Pratiwi NW, Pato U, Saryono. 2020. Molecular identification of amylase-producing thermophilic bacteria isolated from Bukit Gadang Hot Spring, West Sumatra, Indonesia. Biodiversitas 21: 994-1000. Amylase is one of the hydrolytic enzymes that is widely used in a wide number of industrial processes such as food, fermentation, textile, paper, detergent, and pharmaceutical industries. Amylase produced by thermophilic bacteria may be thermostable, which is very beneficial in several applications requiring high temperature, for example, the process of gelatinization, liquefaction, and saccharification are performed in high temperature involved in the starch processing. In this study, the amylase-producing ability of thermophilic bacteria isolated from Bukit Gadang hot spring, West Sumatra, Indonesia, was checked and followed by molecular identification. Thirteen isolates that were successfully isolated from the hot springs were microscopically and macroscopically characterized, biochemically tested, and determined their amylase enzyme activity both qualitatively and quantitatively. The isolate that performed the best amylase activity was identified using the molecular technique. The DNA sequencing was carried out in 16S rRNA and continued with BLAST search for species identification. The result of molecular identification showed that the isolate with the best amylase activity was identified as Bacillus licheniformis. The optimum amylase production (231.33 U/ml) and the best enzyme-specific activity (101.79 U/mg) were obtained at the incubation time of 36 hours.

Black seed oil (BSO) or Nigella sativa contains numerous bioactive components, in which thymoquinone (TQ) becomes a functional key compound and serves as an analytical marker. With its non-polar characteristic, lipid-based delivery systems can be a solution to improve the solubility of BSO. Thus, it is necessary to have a valid basis for TQ quantification, especially in the emulsion as the delivery system of BSO. This study aimed to validate a Gas Chromatography-Flame Ionization Detector (GC-FID) method for quantifying TQ, and subsequently employ the method to evaluate TQ extraction from BSO and BSO-containing emulsion and determine the entrapment efficiency of the emulsion. The method indicated a linearity between 10 and 1280 µg/ml with detection and quantification limits of 13,59 and 41,19 µg/ml, respectively. The extraction of TQ with the sample:methanol ratio of 1:9 and 30-min centrifugation yielded the maximum TQ recovery from BSO and BSO-containing emulsion. The entrapment efficiency in emulsion reached 64,83% obtained with the density-changing centrifugation method. Overall, this validated GC-FID method demonstrated that the selected condition in the methanol extraction could effectively separate TQ from both BSO and its emulsion matrices and support the determination of the entrapment efficiency of the BSO-containing emulsion.

Lipid‐based nanodelivery systems are now widely used in the pharmaceutical and food industries to enhance the delivery of bioactive compounds by leveraging the properties of lipids. Nanostructured lipid carriers (NLC), as one of the lipid‐based nano‐delivery systems, employs a blend of solid and liquid lipids, which improves the solubility, stability, and bioavailability of bioactive substances. This study aimed to optimize the NLC containing thymoquinone‐rich oil (NLC‐TQO) formulation using the Box–Behnken design; assess its antioxidant activity and oxidative stability by measuring 2,2‐diphenyl−1‐picrylhydrazyl (DPPH) radical scavenging activity, thymoquinone (TQ), and tocopherol contents over 28‐day storage; and evaluate the impact of incorporating beta‐carotene as singlet oxygen quencher on the oxidative stability of the NLC‐TQO. The optimized formulation involved 4.16% lipids (glyceryl monostearate and TQO), 5.85% Tween 80 as the surfactant, and 8.20 min of ultrasonication. NLC formulations demonstrated better DPPH activity retention than the emulsions, with cold and dark storage conditions being the most effective for preserving antioxidant activity. TQ stability in the NLC was observed at elevated temperatures without light, with around 50% remaining intact. However, TQ degraded rapidly under light, almost entirely by day 7. Gamma‐tocopherol exhibited better stability than alpha‐tocopherol, especially under light. The addition of beta‐carotene enhanced NLC‐TQO's oxidative stability. These findings revealed the potential of the NLC formulation as an effective delivery system for TQ with better oxidative protection compared to emulsions, making it a promising option for pharmaceutical and food industry applications.

Saryono, Novianty R, Suraya N, Piska F, Devi S, Pratiwi NW, Ardhi A. 2022. Molecular identification of cellulase-producing thermophilic fungi isolated from Sungai Pinang hot spring, Riau Province, Indonesia. Biodiversitas 23: 1457-1465. Thermostable cellulolytic enzymes have become a subject of interest in industrial processes due to their ability to degrade cellulosic polysaccharides at elevated temperatures produced by microorganisms such as fungi and bacteria. In the present study, cellulase-producing thermophilic fungi were isolated and identified from Sungai Pinang hot spring, Riau Province, Indonesia. Morphological identification was carried out by macroscopic and microscopic observations. The ability of the thermophilic fungi to produce cellulase was determined using the clear zone test on carboxymethyl cellulose medium with a congo red staining. Isolate with the highest activity was identified molecularly using universal primers ITS1F and ITS4R. The results showed 19 isolates were morphologically identified as Aspergillus sp. and Penicillium sp. Based on qualitative testing, 3 of the19 isolates showed cellulase activity. The isolate performing the most considerable cellulase was LBKURCC293, which was identified as Aspergillus fumigatus with a cellulase activity of 2.6 x 10^-2 IU/mL and a specific cellulase activity 8.0 x 10^-3 IU/mg protein after 96 days of incubation.

In Indonesia, wilting disease in banana due toFusariumhas spread in several areas. In addition, fungi, bacteria, and actinomycetes are also known to cause the disease. In this research, isolation and identification of bacteria and actinomysetes causing the wilting of rot and rhizosphere were done. Identification used several stages of biochemical tests. There were 40 bacterial isolates with 9 generas, which werePseudomonassp.,Xanthomonassp.,Caulobactersp.,Erwiniasp.,Eschericiasp.,Ralstoniasp.,Neisseriasp.,Staphylococcussp., andProteussp. Whilst 18 isolates of actinomycetes were obtained with 7 generas, includingNocardiasp.,Actinobiosporasp.,Nocardiopsissp.,Streptomycessp.,Streptoverticilliumsp.,Streptosporangiumsp., andMicrobisporasp.

Ardhi A, Ahmad KC, Novrianti H, Husna EY, Yulis M, Pratiwi NW, Saryono. 2019. Hydrolytic enzymes-producing ability of species of actinomycetes and bacteria associated with wilted banana plants (Musa sp.). Biodiversitas 20: 1147-1153. Banana plants contain many nutrients that enable microbes to grow and attack them, causing wilting disease. Microbes growing on the stumps and soil around banana plants are believed to have the ability to produce hydrolytic enzymes. The purpose of this study was to determine the ability of actinomycetes and bacteria isolated from the stumps and soil of wilted banana plants in producing hydrolytic enzymes, namely cellulase, inulinase, amylase, and protease. The confirmation tests of hydrolytic enzymes-producing ability were conducted by inoculating the microbes into media containing CMC, inulin, starch, and skim milk, using the method of paper disc diffusion. From the subculture results, there were 18 isolates of actinomycetes which have been identified as Nocardia, Actinobiospora, Nocardiopsis, Streptomyces, Streptoverticillium, Streptosporangium, and Microbiospora, as well as 40 bacterial isolates with 9 genera of bacteria, namely Xanthomonas, Erwinia, Pesudomonas, Proteus, Ralstonia, Escherichia, Staphylococcus, Caulobacter, and Neisseria, were found. As many as 8 actinomycetes and 40 bacterial isolates indicated the ability to degrade amylum, 39 bacterial and 18 actinomycetes isolates could degrade cellulose, 34 bacterial and 13 actinomycetes isolates could degrade inulin. The highest cellulase ratio was shown by Nocardia sp. LBKURCC101 (3.43) and Ralstonia sp. LBKURCC112 (3.90). The actinomycetes isolate of Nocardia sp. LBKURCC104 and bacteria Pseudomonas sp. LBKURCC133 gave the highest inulinase ratio of 3.36 and 3.47 respectively. In selective amylase media, the highest ratio of 3.10 and 3.80 was found in actinomycetes Nocardia sp. LBKURCC104 and bacteria Erwinia sp. LBKURCC125.