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Microorganisms as cell factories in producing a product are strongly influenced by their metabolism. engineering microbial metabolism by increasing coenzymes that play a role in enzyme activity. Thiamine diphosphate is one of the coenzymes that are commonly found in the metabolic pathways of microbial cells. Increasing the thiamine formation pathway as a precursor in the thiamine metabolic pathway is a strategy in this study. Enhancing thiamine accumulation in Escherichia coli culture by inducing oxygenation level and deleting rpoS was investigated. The investigation was conducted by comparing the cultivation of Escherichia coli BW25113 (parent strain) and BW25113-∆rpoS (rpoS mutant) cultures under aerobic conditions at different shaking rotation rates of 150 and 200 rpm. The measured parameters were thiamine accumulation, dry cell weight, acetate concentration and glucose consumption of the cultures. Inducing oxygenation level of parent strain cultures through increasing shaking rotation rate from 150 to 200 rpm induced 40 % thiamine accumulation. Meanwhile, deletion of rpoS increased 9,5 % thiamine accumulation compared to parent strain culture

Bio-based fungicides with nanotechnology delivery systems employing bacterial products, such as antifungal compounds, could be an alternative substitution for synthetic fungicides. Antifungal activity of extract from B. subtilis strain CR.9 and its nanoemulsion formula using medium-chain triglycerides (MCT) and Tween-80 was evaluated in vitro and in planta effectiveness against Fusarium oxysporum f. sp. glycines associated with soybean plants. For this purpose, the antifungal compounds from bacterial culture were recovered using ethyl acetate as an organic solvent. The fungitoxic activity of antifungal compounds strains CR.9 demonstrated fungal growth inhibition at 394.12 µg/mL (IC50), 250 µg/mL (MICEE), and 100 µg/mL (MICnanoemulsion), respectively. The EtOAc extract (EE)-nanoemulsion formula developed with a ratio of 2:1 (MCT: Tween-80) showed homogenous size and stability for 25 days without creaming, sedimentation, or separate layers. Moreover, seedlings treatment and soil amendment of EE-nanoemulsion performed high efficacy in suppressing wilt and in agreement with commercial fungicide, Dithane M−45. Overall, the antifungal properties of strain CR.9 may have potency as a bio-based fungicide in plant diseases biocontrol strategy.

Biosurfactants are a class of amphipathic molecules that various microorganisms can produce. Biosurfactants are used as biopesticides and biocontrol agents because they have antimicrobial activity, especially as antifungal agents in several species of fungal pathogens such as Ganoderma boninense and Fusarium sp. that attack crops. This study aims to detect the biosurfactant activity of Bacillus sp. and its potential as an antifungal agent against the fungi Ganoderma boninense and Fusarium sp. Biosurfactants were produced in mineral salt medium (MSM) by harvesting cell-free supernatants. Screening of biosurfactant-producing isolates was carried out using an oil-spreading assay, a hemolysis assay, and an emulsification index. The antifungal activity of the isolates was then tested using the agar diffusion method. The LP04 isolate was closely related to Bacillus thuringiensis with a 99% similarity level. It has the potential to have biosurfactant activity, which is characterized by a positive result on the oil spreading assay test and has an emulsification index of 48.33±2.87%. The cell-free supernatants of the bacterial isolate were able to inhibit the growth of Ganoderma boninense and Fusarium sp. with growth inhibition rates of 51.11% and 56.92%, respectively.

Vanillin is one of the most important flavoring agents worldwide. Currently, consumers' awareness and concern for biovanillin production has been increasing. This study aimed to screen the potential of clove rhizospheric bacteria isolates producing vanillin through a biotransformation process of eugenol and to conduct the preliminary optimization of the biotransformation condition. Twenty-eight bacteria isolates were screened for their capability to transform eugenol into vanillin. BKL 15 isolate, which was identified as Lysinibacillus xylanilyticus, was selected as the highest vanillin producer among the isolates. The optimum molar yield of vanillin produced by the selected isolate was 4.99% (1.11 g/L) after 168 hours of biotransformation process in the medium consisting of TSB (30 g/L), eugenol (24 g/L), yeast extract (20 g/L), and concentration of casamino acid (20 g/L). Throughout the publications we have read, this is the first report of L. xylanolyticus that produces vanillin.

The β-glucanase enzyme is an enzyme protein that can hydrolyze β-glucan, one of the main components of the fungal cell wall. This enzyme protein is produced by several bacteria, one of which is B. subtilis. The three-dimensional (3D) structure of proteins is necessary to understand their properties and functions of proteins. Enzyme proteins can be analyzed for their structure and function using in silico method. This study aims to detect the β-glucanase gene from B. subtilis W3.15 and analyze it using the in silico method. The methods in this research are homology modeling and molecular docking analyses. Modeling was carried out using the SWISS-MODEL server and docking analysis using the PLANTS 1.1 program. Modeling the β-glucanase enzyme is based on the template of the β-glucanase enzyme protein model with PDB code 3o5s. The results of sequence alignment and model visualization were quite good as indicated by the model having a Ramachandran Plot value in the favored area of 91.10 %, a MolProbity score of 0.95, and a QMEAN value of 0.90 ± 0.06. The β-glucanase enzyme model was then docked using the PLANTS1.1 program with native ligand B3P, 1,4-β-D-Glucan, D-glucose, β-D-Glucan from oats, and N-Acetyl glucosamine. The results of docking analysis showed that the β-glucan ligand (β-D-glucan from oats) used as a substrate in the cultivation of isolate B. subtilis W3.15 had a better binding energy prediction value compared to the B3P ligand, which is a natural ligand in the template proteins.

Soybean Fusarium wilt and root rot disease caused by a necrotrophic ascomycete pathogen, F. oxysporum, triggered severe damage to the plant tissues and organs and impacted heavy losses. Biocontrol agents, Bacillus subtilis, were commonly used to produce a broad spectrum of antifungal substances and were gradually used in biocontrol studies for plant disease management. Investigation and determination of the inhibiting mechanism of antifungal substance produced by B. subtilis on F. oxysporum should be done to protect the soybean plant. This study revealed that basal nutrient broth (NB) gives the best antifungal activity. The stationary phase of the bacterial growth curve was obtained on two days of cultivation and showed the maximum antifungal activity against F. oxysporum. Ethyl acetate (EA) extraction of bacterial supernatant generated crude EA extract, which showed half inhibition (IC50) at 306.42 µg/ml obtained from the dose-response regression curve. Post-treatment mycelia of F. oxysporum with bacterial extract were demonstrated as hyphal deformation followed by malondialdehyde (MDA) accumulation. Furthermore, cellular leakage on fungal cells that may be triggered by antifungal compounds from strain W3.15 occurred. Last, the related antifungal compounds were predicted to be epicatechin and benzophenone from the LC-MS/MS analysis of crude EA extract. Accordingly, the biocontrol agent B. subtilis strain W3.15 promises a strong potency for biofungicide development.

Eco-enzymes are one of the potential sources for obtaining amylolytic bacterial isolates. The study aims to screen amylolytic bacteria from eco-enzymes, characterize semi-purification amylase, and identify amylolytic bacteria molecularly using the 16S rRNA gene. Screening for amylolytic bacteria was carried out by measuring the amylolytic index on a Nutrient agar medium containing 1% tapioca starch. The amylolytic isolate which had the highest index and was non-pathogenic was selected for the amylase characterization process. Testing of amylase activity was carried out using the Bernfeld method while the protein enzymes were measured using the Bradford method. The extracellular extract was concentrated using ammonium sulfate precipitation. PKL2 is gram-positive bacteria that was derived from eco-enzymes with the highest amylolytic indexes of 1.77, which were not pathogenic on the blood agar test. Optimum amylase was produced by PKL2 at the stationary phase at 21 h. The optimum pH and temperature of the amylase activity were observed to be 7.0 and 50°C, respectively. The amylase enzyme from PKL2 increased its purity 1.82-fold upon precipitation of ammonium sulfate at a concentration of 60%. Identification of bacteria based on molecular identification showed that PKL2 obtained was putatively identified as Bacillus amyloliquefaciens. Keywords: Amylase activity, Bacillus amyloliquefaciens, eco-enzyme, optimum pH

This study aimed to obtain a functional lipase (LipRM) from Ralstonia pickettii BK6 through a co-expression involving its foldase. The ORF of the LipRM was 999 bp while the gene encoding of lipase-specific foldase (LifRM) was 1,030 bp. LipRM and LifRM genes were cloned into a plasmid and were successfully co-expressed in Escherichia coli strains to produce functional LipRM. Enzyme activity from partially purified enzymes showed quite surprising results, LipRM activity in E. coli BL21 (DE3) was 25.84 U/ml, while the other strains (DH5α, HB101, S17-1λpir) were 628.98 U/ml, 761 U/ml, and 1206.46 U/ml, respectively. The highest relative activity of LipRM was found at 50-55°C and pH 7-8 with pNP-laurate (C12) as the preferred substrate specificity. LipRM activity was enhanced sharply in the presence of 30% organic solvents (methanol and ethanol) but decreased by more than 50% in the presence of detergents. This study was the first to report heterologous expression of Ralstonia pickettii lipase employing its native foldase resulting in functional lipase from subfamily I.2.

Oil palm plantations are the most invasive land use changes in Southeast Asia. It must have affected unique natural biodiversity. This study aimed to investigate the diversity of soil bacteria based on 16S rRNA gene profiles from tropical forest and oil palm plantation in Jambi Province, Indonesia. Soil sample was taken from tropical forest and oil palm plantation from Jambi province, Indonesia. The forest site is in Bukit Duabelas National Park, and the nearby oil palm plantation is in Sarolangun District, Jambi Province, Indonesia. The diversity of bacterial communities from topsoil was studied using Denaturing gradient gel electrophoresis (DGGE) of 16S rRNA gene and common biodiversity indices. PCR amplification of 16S rRNA gene was successfully conducted primers-using 33F/ 518R primers. Phylogenetic approach was used for revealing the community shift of bacterial phyla and genera in both areas. Phylogenetic analysis showed there were 4 phyla of bacteria i.e., Firmicutes, Alphaproteobacteria, Gammaproteobacteria, and Actinobacteria, respectively. Actinobacteria was the most dominant group in both areas. The composition of soil bacterial community in the oil palm plantation, based on total number of bands 16S rRNA generated from DGGE was richer than that in the Bukit Dua Belas National Park. It was probably caused by plantation year circle more than 10 years and routine activities during the plantation management, such as applications of agricultural lime, herbicide and fertilizer.

Abstract: Chitinolytic actinobacteria are currently more widely used because of their ability as the biological control agents to the pathogenic fungi, especially in horticultural and plantation crops. This research was conducted to obtain isolates of chitinolytic soil actinobacteria from the rhizosphere of the rubber plant (Hevea brasiliensis) area in IPB University. Antifungal activities from these actinobacteria hopely able to inhibit the growth of plant pathogenic fungi in Vitro on chitin agar media. Fusarium oxysporum and Sclerotium rolfsii are used in the inhibition test of chitinolytic actinobacteria. The results successfully obtained 16 isolates of actinobacteria were grew on Humic Acid Vitamin (HV) agar. It showed that six of 16 actinobacteria isolates were able to produce inhibition zones to the growth of hyphae of pathogenic fungi on potato dextrose agar (PDA). KK-15 and KK-07 isolates were able to produce the largest inhibition percentages in F. oxysporum and S. rolfsii. Based on the chitinolytic index (CI) values, KK-15 and KK-07 isolates produced CI values of 1.25 and 1.5, respectively. The morphological characteristics and Gram staining of both KK-15 and KK-07 isolates are closely relative with Streptomyces sp. Abstrak: Bakteri kitinolitik saat ini banyak diteliti karena kemampuannya sebagai agens pengendali hayati jamur patogen khususnya pada tanaman hortikultura dan perkebunan. Penelitian ini dilakukan untuk mendapatkan isolat-isolat bakteri kitinolitik asal tanah dari bagian perakaran tanaman karet (Hevea brasiliensis) di daerah perkebunan karet Institut Pertanian Bogor (IPB). Aktivitas antifungi dari bakteri ini diharapkan mampu menghambat pertumbuhan jamur patogen tanaman secara in Vitro pada media agar-agar kitin. Fusarium oxysporum dan Sclerotium rolfsii digunakan dalam uji hambat aktinobakteri kitinolitik. Hasil penelitian memperoleh 16 isolat aktinobakteri berhasil diisolasi dengan menggunakan media agar-agar Humic Acid Vitamin (HV), dan dari 16 isolat tersebut, enam isolat mampu menghasilkan zona hambat terhadap pertumbuhan hifa dari kedua jamur patogen pada media Potato Dextrose Agar (PDA) secara in Vitro. Isolat KK-15 dan KK-07 mampu menghasilkan diameter hambatan terbesar pada jamur F. oxysporum dan S. rolfsii. Berdasarkan nilai index kitinolitik (IK), isolat KK-15 dan KK-07 menghasilkan nilai IK sebesar 1,25 dan 1,5 secara berurutan. Karakteristik morfologi dan pewarnaan Gram dari kedua isolat yaitu KK-15 dan KK-07 memiliki kedekatan dengan kelompok Streptomyces spp.

Chitinolytic bacteria are bacteria that have chitinolytic activity, which is able to hydrolysis the composition of chitin which composes many fungal cell walls. Chitinolytic bacteria are currently more widely used because of their ability as a biological control agent to the pathogenic fungi especially in horticultural and plantation crops. This research was conducted with the aim of obtaining isolates of chitinolytic bacteria that were able to inhibit the growth of plant pathogenic fungi in Vitro on chitin agar media. Fusarium oxysporum, Sclerotium rolfsii, and Rhizoctonia solanii are used in the inhibition test of chitinolytic bacteria. Bacteria were isolated and screened from the soil of Bukit Dua Belas National Park and Oil Palm Plantations in Jambi using 0.3% chitin agar media. The results showed that two of 10 bacterial isolates were able to produce inhibition zones to the growth of hyphae of pathogenic fungi on potato dextrose agar (PDA) media. TB04-13 isolate was able to produce the largest inhibition in F. oxysporum and R. solanii about 42% and 42.05% respectively, while TB04-15 isolate produced the biggest inhibition in S. Rolfsii ranged to 25.50%. Based on the chitinolytic index (CI) values, isolates TB04-13 and TB04-15 produced CI values ​​of 1.60 and 0.63, respectively. The morphological characteristics and Gram staining of both TB04-13 and TB04-15 chitinolytic isolates are included in rod-shaped and Gram-positive bacteria. Both of these isolates can be used as antifungal-producing candidates for plant pathogenic fungi in Indonesia.

Endophytic bacteria isolated from plant tissues can produce the same secondary metabolites as their host plants. One of the metabolites that the bacteria can produce is antioxidants. This research aimed to analyze and measure the antioxidant activities of two endophytic bacteria, i.e. Bacillus siamensis HMB1 and Bacillus aryabhattai HMD4 cultures, derived from Hoya multiflora Blume plant, a tropical epiphytic plant species that grows in Indonesia, and to identify their cellular effects on Schizosaccharomyces pombe. The active compounds went through extraction process, and the antioxidant activities were measured, the extracts went under phytochemical analysis, and their phenol and flavonoid contents were measured. In vitro analysis was carried out using S. pombe. The results of this research indicated that both cultures had antioxidant activities, where HMB1 showed the highest IC50 value (51.18 mg/ml) among all. In vitro analysis indicated that HMD4 bacterial crude extract in 250 ppm concentration showed the highest resistance effect and significantly enhanced S. pombe growth. In addition, the results of the LC-MS analysis suggested that a total of 14 compounds potentially had antioxidant activity.

Colletotrichum capsici and Fusarium oxysporum are pathogenic fungi that cause anthracnose disease on chili plants (Capsicum annum L.) which can decrease the productivity of chili. The control of the fungus attack is carried out by biocontrol agent of the fungi utilizing chitinase-producing bacteria. Chitinase is an enzyme capable of destroying the fungal cell wall composed of chitin compounds. The aims of the research were to select and to characterize chitinase producing bacteria as biological control agent of Colletotrichum capsici and Fusarium oxysporum. Several methods were carried out in this research, among others: isolation of chitinase bacteria, characterization of chitinase bacteria, measurement of enzyme activity, bacterial antagonistic with pathogenic fungi, observation of fungal hypha damage, and identification of 16S rRNA. The BAE36 and BAD211 isolates are chitinase bacteria isolated from chili plant rhizosphere. The isolate belongs to the Gram-negative bacteria. The inhibitory properties of BAE36 and BAD211 against F. oxysporum and C. capsici are on a scale of 3 (5175%). The percentage of inhibitory of BAE36 isolate was 66.1% capable of inhibiting the growth of C. capsici and 55% capable of inhibiting the growth of F. oxysporum. The hyphae of C. capsici fungus on the antagonistic test showed a thick and the surface of the hyphae was wavy while the F. oxysporum hyphae was thin and looks empty. Identification of isolate with 16S rRNA described that 99% of BAE36 and BAD211 isolates were similar to Lysobacter enzymogenes. Precipitation of chitinase enzyme of Lysobacter enzymogenes with 30% ammonium sulphate could increase the enzyme activity. The enzyme precipitation could inhibit the growth of mycelia fungi C. capsici and F. oxysporum.

Cow urine contains urea as nitrogen source, therefore it can be expected to isolate the beneficial bacteria for plants, for example indole-3-acetic acid (IAA) or auxin producing bacteria. The objective of research was to obtain IAA producing bacteria from cow urine, to characterize bacterial isolate, and to measure its ability to stimulate the growth of green bean seedlings (Vigna radiata). The methods used in this study were collecting urine from cow cattle, obtaining IAA-pro-ducing bacteria from urine, measuring IAA using Salkowski method, and applying selected bacterial supernatants on green bean seedling plants. The number of IAA producing bacteria that was successfully purified was 18 isolates. There are five isolates, namely US 5, BS1, BS 2, BS 4 and BS 5 which have the ability to solubelize phosphate on Pikovskaya agar. The five isolates were also able to fix free nitro-gen on N Free media and did not show hypersensitivity on tobacco leaves. The results of the growth of isolates in blood agar showed positive for US 5 and BS 2 as beta hemolysin producers. Further-more, isolate BS 4 was chosen to produce exogenous IAA quantita-tively. Isolate BS 4 produced IAA 6.364 ppm at the 45 h incubation at stationary phase. The use of BS 4 supernatant on green bean seed-lings showed an effect on plant height and lateral root length better than control (without treatment) on 6 days after planting. Morpho-logical characteristic of isolate BS 4 was rod shape, Gram positive, endospore producing, aerobic, and had similarity with genus Bacillus

Pengolahan inasua yang dilakukan masyarakat Teon, Nila, dan Serua di Maluku terdiri atas inasua tanpa nira kelapa dan inasua nira kelapa. Kedua produk fermentasi ini memiliki karakteristik sensorik dan masa simpan yang berbeda. Karakteristik sensorik bahan pangan sangat ditentukan oleh kadar asam amino dan asam lemak dalam pangan tersebut. Penelitian ini bertujuan untuk mengkarakterisasi profil asam amino dan asam lemak dalam kedua jenis inasua. Sampel inasua menggunakan ikan gurara (Lutjanus vitta) sebagai bahan dasar yang diambil dari pengrajin di Desa Layeni, Maluku Tengah. Analisis kadar asam amino menggunakan High Performance Liquid Chromatography (HPLC), sedangkan kadar asam lemak menggunakan Gas Chromatography (GC). Hasil penelitian menunjukkan bahwa kadar asam amino dan asam lemak meningkat sejalan bertambahnya waktu fermentasi. Kadar asam amino total inasua tanpa nira adalah 20,96 %, sedangkan inasua nira hanya mencapai 15,31%. Kadar asam lemak total inasua nira adalah 87,48 %, sedangkan inasua tanpa nira hanya mencapai 58,59 %. Asam amino tertinggi pada kedua inasua adalah asam glutamat, sedangkan asam lemak tertinggi adalah asam palmitat. Profil asam amino dan asam lemak diperlukan sebagai referensi untuk memperbaiki nilai nutrisi dan cita rasa inasua sebagai salah satu produk pangan lokal di Maluku. Kata kunci : Asam glutamat, asam palmitat, karakteristik sensorik, nira kelapa DOI : https://doi.org/10.33005/jtp.v15i1.2716

Proteases are among the most important enzymes in both food and non-food industries taking up almost 60% of the world enzyme market. This enzyme has been used for many industrial processes, especially in the detergent industry. The purpose of this study was to characterize the protease from Bacillus licheniformis F11.1 as a bio-detergent agent. An enzyme assay of protease activity was used to assess and characterize the protease enzyme from B. licheniformis F11.1. It showed that the highest pH protease activity for alkaline protease occurred at pH 8.0 with a value of 35.00 U/mL. Under incubation temperature, the protease had the highest activity at 50 °C with a value of 24.46 U/mL. Protease activity was inhibited by Ca2+, Mn2+, K+, and Na+ ions at concentrations of 5 mM. Protease activity can be enhanced by these ions at concentrations of 2 mM. Protease stability can be measured from half-life. Under an incubation temperature of 50 °C, the half- life of the protease at pH 8, 9, and 10 was 108 min, 114 min, and 98 min, respectively. The assay for enzyme stability with an incubation temperature of 60 °C showed half-lives of 92 minutes, 56 minutes, and 61 minutes for pH 6, 9, and 10, respectively. This enzyme was found to be stable with the addition of detergent compounds such as sodium dodecyl sulfate (SDS), Triton X-100, ethylenediaminetetraacetic acid (EDTA), and hydrogen peroxide; all under low concentrations. Determination of the molecular weight using SDS- PAGE and zymogram found the molecular weight was 32.90-35.16 kDa. These results showed that the alkaline protease from B. licheniformis F11.1 can be used as a bio-detergent because of its tolerance to various detergent compounds.

Based on the raw materials, inasua consists of two types namely inasua with sap and inasua without sap. Research of inasua with sap has never been done and considered as the novelty of this research. The sensory characteristics and shelf life of two types of inasua were different. The research aims to analyze the microbiological and physicochemical characteristics of two types of inasua during fermentation. The microbiological analyzes include the total number of bacteria and lactic acid bacteria, while physicochemical analyzes include temperature, pH, water activity, proximate analysis, salt, alcohol, histamine, amino acids and fatty acids contents. The total number of bacteria and lactic acid bacteria has decreased during fermentation. At the end of the fermentation the total number of bacteria and lactic acid bacteria inasua with sap were 3.2x107 CFU/g and 3.0x107 CFU/g, while inasua without sap were 5.4x105CFU/g and 3.5x105 CFU/g, respectively. The moisture, protein, alcohol contents and water activity decreased, otherwise the salt, fat, ash, amino acids, and fatty acids contents increased during fermentation. Generally, microbiological and physicochemical characteristics of inasua with sap was better than inasua without sap. The results of this research to improve the quality of this fermentation product in the future.

Some of the methanotrophic bacteria and N2O reducing bacteria have been proven to be able to support the plant growth and increase the productivity of paddy. However effect of the methanotrophic and N2O reducing bacteria application as a biofertilizer to indigenous N2O reducing bacteria is still not well known yet. The aim of this study was to analyze the diversity of N2O reducing bacteria in lowland paddy soil based on a nosZ gene. Soil samples were taken from lowland paddy soils in Pelabuhan Ratu Sukabumi, West Java, Indonesia. There were two treatments for the paddy field soil, ie. biofertilizer-treated field 20% fertilizer (50 kg/ha) with the addition of biofertilizer and 100% fertilizer. PCR amplification of nosZ gene was successfully conducted using nosZF and nosZR primer pair. Denaturing Gradient Gel Electrophoresis (DGGE) process was conducted at 150 V for 5.5h. There were three differences nosZ bands were sequenced. The phylogenetic analysis showed that they were close to uncultured bacteria. Microbial diversity in the biofertilizer-treated field was higher than that of in the 100% fertilizer-treated field. The biofertilizer treatment has higher in microbial diversity than that of applied non-biofertilizer paddy fields. This research might have impact in the application of biofertilizers due to the emission of N2O as a green house gas from paddy fields farming activity. The biofertilizer has great potential application in sustainable environmental friendly agriculture systems.

Alterations in the use of land for oil palm plantations can change the domination and activity of soil bacteria. More specifically, alteration in soil microbial communities can directly affect soil ecosystem functioning, particularly with respect to carbon and nitrogen cycles. Nitrogen can be a limiting nutrient, and the availability of nitrogen in the soil environment becomes a major factor in controlling the production of biomass. This research project aimed at studying the abundance of nitrogen-fixing, nitrogen-oxidizing, nitrogen-reducing, and ammonifying bacteria based on their functional genes in the tropical rain forests of Taman Nasional Bukit Duabelas (TNBD) and the oil palm plantations in Sarolangun Jambi. Samples were collected in November 2015. Soil sampling was performed randomly at three points representing each area of ​​the tropical rainforests of TNBD and the seven- to eight-year-old oil palm plantations. Soil samples were collected using a soil sample core from 0–15 cm below the surface with depth strata of 0–5 cm, 5–10 cm, and 10–15 cm. Composite assessment was conducted on samples from each point corresponding to each respective depth strata. Soil samples were stored at -20ºC prior to testing. Microbial abundance was measured using the most probable number (MPN) method. The abundance of microbes that play a role in nitrogen metabolism between strata of 5–10 cm and 10–15 cm does not appear to be different. The highest abundance of microbes in oil palm plantation land in Jambi was found in samples with nitrifying bacteria, later followed by denitrifying, nitrogen-fixing, and ammonifying bacteria. Ultimately, it was found that microbial abundance in oil palm plantations was higher than the corresponding rates in samples from tropical rainforests.

Nata de coco is known as a gelatinous substance, white to creamy-yellow, firm, glossy and not sticky, produced by some bacteria, which forms on the surface of coconut water medium during fermentation. Acetobacter xylinum (current name: Gluconacetobacter xylinus) is the common bacteria which synthesized nata de coco. Besides coconut water, there are some alternatives for making nata, such as cassava. Gluconacetobacter sp. was employed in this study to produce nata de coco from cassava hydrolysate medium (U) and compared it qualitatively and quantitatively to coconut water medium (K). In U medium, glucose was the main product derived from hydrolysis of cassava. Fermentation was conducted three times with each former fermentations became sources of inocula for the next fermentations, respectively. All data were analysed with IBM SPSS Statistics 23. Fermentation product of nata from U medium were relatively stable in thickness, wet weight, dry weight, yield, water content, and log from total bacteria (quantitative) and in colour, texture, transparency, and surface of nata (qualitative). Glucose was rapidly consumed by bacteria then other sugar (fructose and sucrose). Glucose consumption and nata yield was affected by the number of bacteria. However, nata yield was not significantly influenced by glucose consumption. Nata yield was possibly influenced by other factors such as nutrient content in U medium. Growth dynamics of Gluconacetobacter sp. was measured in log cfu mL-1 on Hassid-Barker Agar (HBA) medium and relative number of 16S rRNA genes. Bacterial growth during fermentation in U medium were relatively more stable than fermentation on K medium although the yield in K medium gradually increased and were higher than U medium.

Objective: To identify bioactive compound in pigeon pea leaves (Cajanus cajan) that inhibits Salmonella thypi (S. thypi). Methods: The leaf sample was powdered and macerated with methanol and fractioned by liquid–liquid extraction using ethyl acetate. The fraction was chromatographed and the isolates were identified for major component with liquid chromatography-mass spectrometry and the antibacterial activity was tested against S. thypi by Kirby–Bauer method. Results: Subfraction 1 from the ethyl acetate fraction formed a yellowish solid with m/z 272, identified as naringenin. The naringenin-rich fraction shows fairly well inhibitory toward S. thypi in comparison with chloramphenicol. Conclusions: Naringenin shows antibacterial activity and can be developed to treat typhoid.

The condition of starter plays important role in enzyme production. Optimum starter will lead to the optimum yield of enzyme production. The experiments which were aimed to obtain the optimum age for starter of Streptomyces thioluteus TTA 02 SDS 14 from solid as well as liquid medium had been carried out which would be used for transglutaminase production. Medium used for culture maintenance, starter optimization and enzyme production was described by Bahrim. The result showed that S. thioluteus TTA 02 SDS 14 was ready to be used as starter after being cultured on solid medium continued in liquid medium each for 6 days. The enzyme production in a bioreactor using optimized starter produced enzyme with the highest activity after being fermented for 2 days with 150 rpm agitation. The crude enzyme active optimally at 45-50 oC, pH of 6 and no effect of metal ion and inhibitor on enzyme activity.

Inasua is a traditionally product of wet salt fish fermentation produced by Teon, Nila and Serua (TNS) Communities in Central Maluku, Indonesia. The community made this fermented fish to anticipate the lean time when fisherman could not go to sea. The fish that used as inasua raw material is demersal fishes that live around coral reefs, such as Samandar fish (Siganatus guttatus), Gala-gala fish (Lutjanus sp.) and Sikuda fish (Lethrinus ornatus). The objective of the research was to isolate and characterize of bacterial indigenous in Inasua from three producers in Seram Island. The measurement of pH from inasua samples were 5.9, 5.0 and 5.8, respectively. The highest number of lactic acid bacteria was found from Gala – gala inasua was 2,5x107 cfu/g sample. Isolation of all isolates bacteria from inasua showed that a total of 7 isolates of bacteria was obtained from Samadar inasua, 9 isolates from Gala-gala inasua, and 7 isolates from Sikuda inasua. From a total of 23 isolates, only 6 isolates had characteristic as lactic acid bacteria that were Gram positive, negative catalase, and cocci shape. The microscopic characteristics of the isolates are coccid in pairs or uniforms which combine to form tetrads. Carbohydrate utilization test of selected isolate by using API 50 CHB kit indicated that 13 carbohydrates are fermented by these isolates after incubation for 48 hours. The research was concluded that the dominant bacteria in inasua sample is cocci-lactic acid bacteria. Keywords : fermented fish, inasua, lactic acid bacteria, MRSA medium

Streptomyces sp. TTA 02 SDS 14 is a transglutaminase producing bacteria which previously had been screened along with more than one hundred isolates. This research aimed to purify and characterize transglutaminase from this strain. Transglutaminase was purified from crude enzyme by ultrafiltration, Q-Sepharose ion exchange chromatography and Sepacryl S200 size exclusion chromatography sequentially, obtaining yield and purification fold of 1.36% and 27 folds, respectively. The molecular weight of the purified transglutaminase was 72 kDa detected by zymogram gel electrophoresis. The optimum temperature and pH were 50°C and 6. The transglutaminase was stable at 45°C and could be activated in the presence of 5 mM and 10 mM of Na+, K+, Li+,Ca2+, Mg2+, BPB (4-bromo-phenacyl bromide), and IAA (iodo acetamide acid), but the activity was inhibited by the presence of Cu+, Zn2+, and PMSF (phenyl methyl sulfonyl fluoride).

Pyrene degradation and biosurfactant activity by a new strain identified as Gordonia cholesterolivorans AMP 10 were studied. The strain grew well and produced effective biosurfactants in the presence of glucose, sucrose, and crude oil. The biosurfactants production was detected by the decreased surface tension of the medium and emulsification activity. Analysis of microbial growth parameters showed that AMP10 grew best at 50 µg mL-1 pyrene concentration, leading to 96 % degradation of pyrene within 7 days. The result of nested PCR analysis revealed that this isolate possessed the nahAc gene which encodes dioxygenase enzyme for initial degradation of Polycyclic Aromatic Hydrocarbon (PAH). Observation of both tensio-active and emulsifying activities indicated that biosurfactants which produced by AMP 10 when grown on glucose could lower the surface tension of medium from 71.3 mN/m to 24.7 mN/m and formed a stable emulsion in used lubricant oil with an emulsification index (E24) of 74%. According to the results, it is suggested that the bacterial isolates G. cholesterolivorans AMP10 are suitable candidates for bioremediation of PAH-contaminated environments.How to CiteKurniati, T. H., Rusmana, I. Suryani, A. & Mubarik, N. R. (2016). Degradation of Polycyclic Aromatic Hydrocarbon Pyrene by Biosurfactant-Producing Bacteria Gordonia cholesterolivorans AMP 10. Biosaintifika: Journal of Biology & Biology Education, 8(3), 336-343.

Compared to the widely explored antioxidant activity from the clove bud extract, less data are available regarding the potential pharmacological use of clove leaves. Our study aimed to explore the antioxidant activity of clove leaves extract in the cellular level. Thus, we used the yeast Schizosaccharomyces pombe as model organisms. Our data indicate that, following extract treatment (100 ppm), the viability of the stationary phase cells of S. pombe was higher than without extract and that of calorie restriction treatments. 100 ppm extract treatment also increased cell viability against H2O2-induced oxidative stress. Those data indicate that the extract could promote oxidative stress tolerance response in yeast cells, which occurred either during the stationary phase or due to exogenous exposure. Higher dose of extract (500 ppm) showed opposite effects, as cell viability was lower than that without treatment. Analysis toward the mitochondrial activity revealed that the extract did not induce mitochondrial activity unlike the calorie restriction treatment. Based on our data, clove leaf extract promotes oxidative stress tolerance response in the yeast S. pombe, independent to that mitochondrial adaptive ROS signaling which commonly occurs in calorie restriction-induced oxidative stress tolerance response.

Background and Objectives: Inasua is one of the traditional fermented fish products in Maluku, Indonesia. There are twotypes of inasua, i.e. with and without sap. The research aimed to study the succession of lactic acid bacteria (LAB) duringfermentation and microbial composition in inasua. Materials and Methods: The sample of inasua was taken from two traditional producers in Layeni village, Ceram Island.The diversity of lactic acid bacteria was analyzed based on the 16S rRNA gene sequence. Results: The succession of lactic acid bacteria was strongly influenced by the physicochemical characteristics during fermentation.Lactobacillus plantarum was found dominant in both inasuas fermentation processes. At end of fermentation,L. plantarum was still found dominant in inasua with sap while inasua without sap was dominated by Leuconostoc mesenteroides.In addition, Lactobacillus paracasei (LAB) was found only in inasua with sap. The result of Denaturing Gradient Gel Electrophoresis (DGGE) revealed that Lactobacillus was the dominant bacteria in inasua with sap while Staphylococcuswas dominant in inasua without sap. Conclusion: Inasua with sap was found with higher bacterial diversity index and lower evenness and dominance indices, aswell as more complex LAB succession pattern during fermentation and bacterial composition, as opposed to inasua withoutsap.

Use of Chitinolytic Bacteria as Biological Control of Colletotrichum capsici on Chili Plants Colletotrichum capsici is known as the causal agent of anthracnose disease in chili plant and may cause reduction of crop yield. Chitinolytic bacteria, namely Serratia marcescens KAHN 15.12, Bacillus thuringiensis SAHA 12.12, and BAE 36 were reported to have antagonistic activity against C. capsici. Therefore, a study was conducted to determine the potential of chitinolytic bacteria on controlling C. capsici on chili plants in greenhouse experiment. Three bacterial isolates used as biocontrol agent was formulated by using talcum as carrier materials. The methodologies consisted of characterization of bacterial isolates, formulation of biocontrol agent, viability test of bacterial isolate, efficacy of biocontrol agents in the laboratory and in the greenhouse. Disease severity in the laboratory reached 64% when chili treated with isolate formulation of BAE 36. In the greenhouse, BAE 36 isolate formulation and consortium formulation were able to suppress infection of C. capsici; each was indicated by disease incidence of 25% and 50%, respectively. These results indicated that chitinolytic bacterial formulations could be potencial as biocontrol agents of C. capsici.

Chitinolytic bacteria have been reported as biocontrol agents and have the ability to produce chitinase enzymes. The objective of the research was to obtain chitinase producing bacteria that had antagonistic activity to Ganoderma boninense, a causal agent of basal stem rot on oil palm. A total of 63 isolates of chitinase producing bacteria were isolated from soil of Bukit Dua Belas National Park and oil palm plantation in Jambi Province; all was screened for their potency in inhibiting G. boninense in vitro. Three isolates designated TB04-05, SW01-11, and SW02-08 were potentially suppressed and inhibited the mycelium growth of G. boninense in vitro. Based on their specific chitinase activity, these three isolates produced the highest level of chitinase enzyme of 6.3072 U mg-1 protein, 6.0385 U mg-1 protein and 6.1279 U mg-1 protein, respectively after 24 hr incubation. Based on 16S RNA identification, strain TB04-05 had similarity with Bacillus cereus, whereas strains SW01 and SW02-08 had similarity with Bacillus thuringiensis.

Hasil penapisan bakteri penghasil enzim selulase terdahulu mendapatkan isolat PMP 0126 sebagai isolat yang berpotensi yang diisolasi dari limbah pengolahan agar skala UKM di Pamengpeuk, Garut. Isolat tersebut ternyata belum merupakan koloni tunggal, terdiri dari 2 isolat bakteri yaitu PMP 0126Y dan PMP 0126W. Isolat PMP 0126Y memiliki kemampuan mendegradasi selulosa yang lebih besar dibanding PMP 0126W. Tujuan dari penelitian ini adalah untuk memproduksi dan mengkarakterisasi enzim selulase dari isolat PMP 0126Y, serta mengidentifikasi isolat tersebut. Hasil penelitian menunjukkan bahwa enzim selulase diproduksi optimum pada hari ke-3 kultivasi menggunakan medium cair berisi CMC 1%. Enzim kasar yang diperoleh dapat bekerja optimal pada suhu 30 °C dan pH 5, dapat ditingkatkan aktivitasnya dengan ion logam dalam bentuk garam CaCl2 dan ZnCl2 5 mM.. Pemurnian dengan sistem penukar anion dapat meningkatkan aktivitas enzim 15x dengan perolehan 20%. Dari hasil SDS-PAGE terlihat bahwa ada 3 selulase dengan perkiraan berat molekul 39, 30, dan 14 kDa. Enzim kasar ini memiliki kemampuan menghidrolisis limbah pengolahan agar sebaik ketika memecah substrat CMC, yang mengindikasikan bahwa enzim dari isolat ini berpotensi sebagai kandidat agen sakarifikasi pada produksi bioetanol. Identifikasi bakteri dengan 16S-rDNA menunjukkan bahwa isolat ini memiliki kemiripan 96% dengan bakteri Chryseobacterium indologenes McR-1.

Chitin, a common constituent of insect exoskeleton, could be hydrolyzed by chitinase. This research was conducted to select rhizobacteria isolated from the rhizosphere of chili pepper that produced chitinase and to examine their chitinase activity in degrading chitin of the Aphis gossypii. A total of 25 rhizobacteria isolates formed a clear zone when grown on chitin agar. Three of them had the highest chitinolytic index and were identified as Bacillus sp. strain I.5, I.21, and II.14. The II.14 was chosen for characterization of chitinase activity. The isolate showed maximum chitinase activity at 48-h-incubation. Maximum temperature and pH of the chitinase activity were 55°C and 7.0, respectively. The cell culture and the enzyme crude extract of the above three isolates were tested against A. gossypii and the result was compared to the control through microscopic observation. Hydrolytic analysis showed that the enzyme crude extract of these isolates were able to degrade chitin of insect exoskeleton since the first 3-h-incubation. Meanwhile, the cell culture treatment on the chitin showed degrading activity after 12 h (Bacillus sp. strain I.21 and II.14), and 9 h (Bacillus sp. strain I.5). Chitin degradation of A. gossypii exoskeleton by enzyme crude extract was better than the cell culture treatment. Chitinases produced by Bacillus sp. strains I.5, I.21, and II.14 are potential as biocontrol agents for A. gossypii.

Three isolates among 138 sponge-associated bacteria were isolated from Waigeo Island, Raja Ampat West Papua Province, Indonesia, have been shown protease inhibitory activity against subtilisin (serine protease), thermolysin (metalloprotease), and crude extract from pathogenic bacteria (Eschericia coli enteropathogenic/EPEC K.1.1, Staphylococcus aureus, and Pseudomonas aeruginosa). Those three isolates were designated as sponge associated bacteria SAB S-12, SAB S-21, and SAB S-17. A simple casein and Sea Water Complete (SWC) double layer agar method was used to screen the bacteria against pathogenic bacteria producing protease, i.e. EPEC K.1.1, S. aureus, and P. aeruginosa. Among them, SAB S-12 isolate showed no inhibitory zone indicated. The isolate had the highest inhibitory activity against subtilisin and crude extract enzyme of pathogenic bacteria, the inhibitory activity was 91.6 and 98.9%, respectively. In addition, the SAB S-21 isolate had the highest inhibitory activity against thermolysin, it was 70.4%. The optimum pH and temperature for protease inhibition of the three isolates was at pH 7.0-8.0 and 40-50 oC respectively. Based on 16S rRNA gene sequence, the closest related with SAB S-12, SAB-17, and SAB-21 isolates was Providencia sp. (92% identity), Paracoccus sp. (86% identity), and Bacillus sp. (% identity), respectively.

Plant growth promoting rhizobacteria (PGPR) play an important role in improvement of seed germination, root development, and water utilization by plants. These rhizobacteria can stimulate plant growth directly by producing growth hormones or indirectly by producing antifungal compounds/antibiotics to suppress phytopathogenic fungi. The objective of this research was to analyze the diversity of 22 antifungal-producing rhizobacteria of Bacillus sp. isolated from rhizosphere of soybean plant based on Amplified rDNA Restriction Analysis (ARDRA) and 16S rRNA Sequence. Restriction enzymes in ARDRA analysis, HinfI, HaeIII, and RsaI were used to digest 22 16S rDNA amplified from Bacillus sp. genomes. Based on this analysis, genetic diversity of 22 Bacillus sp. producing antifungal compounds were classified into eight different groups. Moreover, six selected isolates randomly from each ARDRA group that have strong activity to suppress fungal growth were analyzed for their 16S rDNA sequences compared with reference strains. The distributions of these isolates were genetically diverse on several species of Bacillus sp. such as B. subtilis, B. cereus, and B. fusiformis. ARDRA is a reliable technique to analyze genetic diversity of Bacillus sp. community in the rhizosphere.

Land with low pH soil spread widely in Indonesia can be used for soybean (Glycine max) cultivation, although the production is low. The use of acid tolerant soybean and acid-Al tolerant nitrogen-fixing bacteria was an alternative way to increase soybean productivity on acid soils. This research was conducted to study the influence of acid-Al tolerant Bradyrhizobium japonicum on growth of Slamet cultivar soybean planted on acid soils in greenhouse. Three strains of acid-Al tolerant B. japonicum, i.e. BJ 11 (19), BJ 11 (5), and BJ 11 (wt), were used in this experiment. The result showed that inoculation of all acid-Al tolerant B. japonicum strains could increase plant height, shoot and root weight, number of flowers, pods, seeds, seeds dry weight, and shoot and seed nitrogen content.

Tobacco Mosaic Tobamovirus (TMV) is one of many important viruses infecting Solanaceous plants including hot pepper in Indonesia. To accomplish and improve the effectiveness of virus management, we used root-colonizing bacteria (rhizobacteria) isolated from healthy hot pepper. Eight rhizobacteria isolates were selected and their capacity in enhancing plant growth and inducing systemic resistance (ISR) against TMV in greenhouse trials were evaluated. The rhizobacteria was applied as seed treatment and soil drench. Bacterized-seedling showed a better growth vigor, fitness and a milder symptom than non-bacterized control plants. The protective effect of rhizobacteria was more pronounced after challenging inoculation by TMV, especially for plants treated by isolates I-6, I-16, and I-35. However, TMV accumulation was slightly affected by bacterial treatment. The rhizobacteria might improved ISR by increasing peroxidase enzyme activity but this depends on the species. Based on whole results, isolate I-35 was the potential plant growth promotion rhizobacteria (PGPR). The I-35 was identified as Bacillus cereus based on morphological characteristics and nucleotide sequences of 16S r-RNA.

Utilization of soil bacteria as biocontrol agent is becoming popular due to its valuable and effective mechanisms to suppress plant pathogenic microbes. We have previously isolated Bacillus sp, designated as Bacillus sp CR64, which exhibited effective plant growth promoting and antifungal activities. In this study, CR64 was examined in inhibiting the growth of Rhizoctonia solani, the causing agent of root rot disease. Partial sequence analysis of 16S rRNA gene revealed that this isolate similar with Bacillus cereus (94%). Furthermore, a gene designated zmaR was detected by means of specific amplification of DNA fragment approximately 950 bp. This fragment was then cloned onto pCRII-TOPO (3.9 kb) and sequenced using DNA sequencer ABI PRISM 310. Sequence analysis revealed that it had highest homology with the ZmaR protein (89% identity; 90% similarity) of B. thuringiensis serovar kurstaki (AAF82729.2). Alignment analysis with other ZmaR sequences from other antibiotic-producing Bacilli exhibited an almost fully conserved region within ZmaR sequences.Key words : PGPR, Bacillus sp CR64, Zwitermicin A, Cloning, Antifungal.

Enteropathogenic Escherichia coli (EPEC) causes gastrointestinal infections in human. EPEC invasion was initiated by attachment and aggressive colonization on intestinal surface. Attachment of EPEC alter the intestine mucosal cells. Despite this, the pathogenic mechanism of EPEC infectior has not been fully understood. This research hypothesizes that extracellular proteolytic enzymes is necessary for EPEC colonization. The enzyme is secreted into gastrointestinal milieu and presumably destroy mucus layer cover the gastrointestinal tract. The objective of this study was to assay EPEC extracellular protease enzyme by using mucin substrate. The activity of EPEC extracellular proteolytic enzyme on 1% mucin substrate was investigated. Non-pathogenic E. coli was used as a negative control. Positive and tentative controls were Yersinia enterocolitica and Salmonella. Ten EPEC strains were assayed, seven of them were able to degrade mucin, and the highest activity was produced by K1.1 strain. Both positive and tentative controls also showed the ability to digest 0.20% mucin.

Protease of two Streptomyces sp. strain were chosen for characterization because of the large clear zone surrounding the colony in nutrient agar media containing 1% (w/v) skim milk. Extracellular protease from the two isolates SLW 8-1 and 45I-3 were characterized following incubation of the isolate in Nutrient Broth media containing skim milk or chicken feather (1%). The optimum activity of the protease SLW 8-1 was at pH 9 and 80 ºC, whereas that of the keratinase was at pH 6.5 and 70 +C. Protease of strain 45I-3 showed its optimum activity at pH 7.5 and 50 ºC whereas the keratinase was at pH 8.5 and 80 ºC.

Bacillus sp. AQ-1 was isolated from household aquarium sediment. The isolate produced extracellular xylanolytic enzymes on xylan containing agar medium. Based on morphological, and physiological analysis, the isolate was identified as Bacillus sp. AQ1. The effect of temperature and pH on isolate growth and xylanase production were observed. The best condition observed for the enzyme production in Luria Broth supplemented with 0.5% oat spelt xylan medium was at 40 °C pH 7. The maximum enzyme production was 0.23 U mL-1 after 20 h of fermentation. Two different medium compositions (A and B) were examined for xylanase production. The maximum growth of the isolate and the xylanase production was better in A medium. Replacing oat spelt xylan in medium A with fruitless oil palm bunch in the medium caused the growth slightly slower than that of in the original formula. However, the xylanase production was 3 times higher in fruitless oil palm bunch medium. Optimum activity of the crude enzyme was observed at 60 °C and pH 7. Each ml of the crude enzyme contained 55.21 U xylanase, 8.12 U amylase and 0.50 U carboxymethylcellulase

Accumulation of feed excess in commercial shrimp ponds due to overfeeding could decrease water quality. Protein and starch are the primary components of shrimp feed. This study was conducted to characterize extracellular proteases and amylases of Bacillus spp. isolated from shrimp ponds. 72 proteolytic and amylolytic Bacillus spp. isolates were screened from shrimp ponds in Karawang, West Java. Ten isolates were selected for further characterization for their growth and ability to reduce total suspended solid generated from commercial shrimp feed. Bacillus sp. DA 5.2.3 and L5 showed excellent activity in reducing total suspended solid, by 37 and 30% respectively. Protease and a-amylase activities of Bacillus sp. DA 5.2.3 isolate were consistently higher than that of L5. Maximum total and specific protease activity of DA 5.2.3 isolate was 2.0 U mL-1 and 40.9 U mg-1 respectively, while the activities of the L5 isolate were 2.1 U mL-1 and 23.0 U mg-1 respectively. Based on its 16S rRNA gene sequences, Bacillus sp. DA 5.2.3 showed 99% similarity to Bacillus cereus XHJ-2-6. Bacillus sp. DA 5.2.3 could potentially be applied to maintain water quality by reducing total suspended solid in water columns of shrimp ponds.

Plant-growth promoting rhizobacteria (PGPR) are rhizosphere associated soil-borne bacteria that can enhance plant growth and inhibit the development of root pathogens. Many soil bacteria have been used as PGPR, and one of them is Bacillus sp. The implementation of PGPR is constrained by genotype fluctuation that makes it inactive on the rhizosphere. Our previous study had characterized and revealed that 11 Bacillus sp. isolated from the soybean plant rhizosphere were PGPR. To asses and compare the genetic diversity of these isolates, Amplified Ribosomal DNA Restriction Analysis (ARDRA) and DNA sequence analysis of 16S rRNA were conducted. The construction of Neighbor-joining trees and bootstrap analysis of 100 resamples of ARDRA and 16S rRNA gene sequences were performed using Treecon software for windows ver. 1.3b. ARDRA analysis was done by using four restriction enzymes (RsaI, HaeIII, CfrI and HinfI), resulting in four phylotypes, respectively phylotype I (Bacillus sp. Cr24, Cr33, Cr64 and Cr68), phylotype II (Bacillus sp. Cr 31 and Cr66), phylotype III (Bacillus sp. Cr44 and Cr71) and phylotype IV (Bacillus sp. Cr67, Cr28 and Cr69). Results of BLASTN from 16S rRNA gene sequences showed that these isolates are genetically diversed. The evolution relationship of Bacillus sp. could be shown by the 16S rRNA gene sequences analysis, while ARDRA based on the digestion sites showed their variability.

Utilization of soil bacteria as biocontrol agent is becoming popular due to its valuable and effective mechanisms to suppress plant pathogenic microbes. We have previously isolated Bacillus sp, designated as Bacillus sp CR64, which exhibited effective plant growth promoting and antifungal activities. In this study, CR64 was examined in inhibiting the growth of Rhizoctonia solani, the causing agent of root rot disease. Partial sequence analysis of 16S rRNA gene revealed that this isolate similar with Bacillus cereus (94%). Furthermore, a gene designated zmaR was detected by means of specific amplification of DNA fragment approximately 950 bp. This fragment was then cloned onto pCRII-TOPO (3.9 kb) and sequenced using DNA sequencer ABI PRISM 310. Sequence analysis revealed that it had highest homology with the ZmaR protein (89% identity; 90% similarity) of B. thuringiensis serovar kurstaki (AAF82729.2). Alignment analysis with other ZmaR sequences from other antibiotic-producing Bacilli exhibited an almost fully conserved region within ZmaR sequences. Key words : PGPR, Bacillus sp CR64, Zwitermicin A, Cloning, Antifungal.

Increased consumption of xylose-glucose and yeast tolerance to lignocellulosic hydrolysate are the keys to the success of second-generation bioethanol production. Candida tropicalis KBKTI 10.5.1 is a new isolated strain that has the ability to ferment xylose. In contrast to Saccharomyces cerevisiae DBY1 which only can produce ethanol from glucose fermentation. The research objective is the application of the genome shuffling method to increase the performance of ethanol production using lignocellulosic hydrolysate. Mutants were selected on xylose and glucose substrates separately and using random amplified polymorphic DNA (RAPD) analysis. The ethanol production using lignocellulosic hydrolysate by parents and mutants was evaluated using a batch fermentation system. Concentrations of ethanol, residual sugars, and by-products such as glycerol, lactate and acetate were measured using HPLC machine equipped with Hiplex H for carbohydrate column and a refraction index detector (RID). Ethanol produced by Fcs1 and Fcs4 mutants on acid hydrolysate increased by 26.58% and 24.17% from parent DBY1, by 14.94% and 21.84% from parent KBKTI 10.5.1. In contrast to the increase in ethanol production on alkaline hydrolysate, Fcs1 and Fcs4 mutants only experienced an increase in ethanol production by 1.35% from the parent KBKTI 10.5.1. Ethanol productivity by Fcs1 and Fcs4 mutants on acid hydrolysate reached 0.042 g/L/h and 0.044 g/L/h. The recombination of the genomes of different yeast species resulted in novel yeast strains that improved resistance performance and ethanol production on lignocellulosic hydrolysates. [ABSTRACT FROM AUTHOR]