BIOTROPIA - The Southeast Asian Journal of Tropical Biology
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LIGHT-COLOR-INDUCED CHANGES IN FATTY ACID BIOSYNTHESIS IN Chlorella sp. STRAIN KS-MA2 IN EARLY STATIONARY GROWTH PHASE
Get PDFOptimization of light supply remains a critical issue in microalgae biotechnology. The impacts of light color on fatty acid production and biosynthesis in microalgae are poorly understood. The aim of this study was to determine the effect of light color on growth and fatty acid content in Chlorella strain KS-MA2. Cells were cultured on F/2 medium and incubated under blue, green, red, or white light. The cells\u27 growth, fatty acid composition, and the expression levels of the ketoacyl synthase 1 (KAS-1), omega-6 desaturase (ω-6 FAD), and omega-3 desaturase (ω-3 FAD) genes were measured at the early stationary growth phase. Results of this study indicated that light color affected cell density and fatty acid profile produced by Chlorella sp. strain KS-MA2. Cells cultured under blue, red, and white light had higher cell density than those cultured under green light. Palmitic acid (38.62 ± 3.29% of biomass dry weight) and linolenic acid (7.96 ± 0.88% of biomass dry weight) were highly accumulated under white light. Stearic acid was dominant under blue light (11.11 ± 0.14% of biomass dry weight), whereas oleic acid was dominant under red light (30.50 ± 0.14% of biomass dry weight). Linoleic acid was highly produced under green and blue light (28.63 ± 1.36% and 26.00 ± 0.81% of biomass dry weight, respectively). KAS-1 and ω-6 FAD were highly expressed under blue light, whereas ω-3 FAD was highly expressed under green light. The production of particular fatty acids of interest from Chlorella could be achieved by shifting color of light used during the incubation of the cell cultures. Blue light is the most suitable light color for producing biomass and stearic acid by Chlorella strain KS-MA2
RESISTANCE AGAINST Aeromonas hydrophila INFECTION AND GROWTH OF SECOND GENERATION (F2) AFRICAN CATFISH (Clarias gariepinus) USING SELECTED MOLECULAR MARKERS
No full textAeromonas hydrophila is a pathogenic bacteria that causes mass mortality in catfish. In previous studies, specific pathogen resistant (SPR), A. hydrophila-resistant African catfish first generation (F1) has been cultivated by marker assisted selection using the major histocompatibility complex (MHC) I as a molecular marker. In this study, growth performance, inheritance of the MHC DNA marker in the second generation (F2) of catfish and disease resistance against A. hydrophila infection were observed. The F2 progenies were produced by crossing F1 fish between themselves. Nursery was performed in 80-L glass aquaria, 4 replications for each cross, at the same initial density, for 2 months of rearing. The results showed that daily growth rate of F2 progenies from the SPR broods was significantly higher than those from broods without the marker. Results of the PCR analysis showed that average number of F2 progenies from SPR broods carrying the MHC marker was about 91% higher than that of control. After the fish reached about 12 cm body length, they were challenged by intramuscularly injecting of 0.1 mL A. hydrophila (LD₅₀: 10⁵ CFU/mL) for 7 days. Results of challenge test showed that survival of F2 offspring from the crosses of SPR broods (77.2%) was about two times higher than those from brood without MHC marker (38.3%). Differential leukocyte count supported the high resistance of F2 progenies from F1 broods having MHC I marker against A. hydrophila infection. In conclusion, African catfish farming carrying MHC marker potentially have higher productivity and reduces fish loss due to infection by A. hydrophila
IDENTIFICATION OF ENDOPHYTIC BACTERIA FROM Curcuma zedoaria BASED ON PROTEIN PROFILE USING MALDI-TOF MASS SPECTROMETRY
Get PDFValid identification of microorganisms is vital information to establish culture collections. Currently, a molecular approach based on 16S rDNA is widely used for bacterial identification. However, this approach is time-consuming and expensive. Matrix-Assisted Laser Desorption Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) allows the identification of microorganisms directly from colonies, and it only takes a few minutes. The aim of this study was to identify endophytic bacteria associated with Curcuma zedoaria based on protein profiles using the MALDI-TOF MS system and to compare the results with 16S rDNA sequencing. Endophytic bacteria were isolated from parts of the medicinal plant C. zedoaria collected from Bogor, West Java, Indonesia. The identification of selected bacteria was performed using protein profiling via MALDI-TOF MS. A total of 66 endophytic bacteria from C. zedoaria were selected for identification. The results of MALDI-TOF MS analysis showed that eleven isolates (16.67%) were correctly identified at the species level, and twenty-three isolates (34.85%) matched the genus level of the molecular approach. These results demonstrate that the MALDI-TOF system is a suitable and feasible approach for bacterial identification, particularly for screening and grouping large numbers of isolates
PHENOTYPIC AND MOLECULAR CHARACTERIZATION OF MULTISHOOTS DEVELOPMENT IN TRANSGENIC Phalaenopsis amabilis (L.) Blume HARBORING 35S::KNAT1 (KNOTTED-LIKE Arabidopsis thaliana 1)
No full textPhalaenopsis amabilis (L.) Blume is one of Indonesian natural orchids which has an aesthetic flower and possesses high economic value. The low multiplication rate and long period of life cycle are the main obstacles to conventionally propagate this orchid. The aims of this research were to analyze the stability of transgenic plant P. amabilis harboring 35S::KNAT1 based on morpho-genomic characterization. KNAT1 gene is reported as a gene that is involved in shoot formation, and it had been successfully introduced into Phalaenopsis amabilis (L.) Blume genome. After seven times regeneration, the confirmation of the transgene existence in the genome is needed to ensure whether the plant could consistently maintain the transgene in its genome and to characterize the shoot development. The experiment was carried out in 3 steps: 1) Co-integration analysis of 35S::KNAT1 into P. amabilis genome; 2) Phenotypic analysis on the multiplication rate, morphological variation, and venation pattern; and 3) Protein profile analysis of transgenic plants. The results showed that the survival rate of putative transgenic was 58.7% on NP0 medium and 62.5% on NP SIM medium. PCR analysis confirmed that 82.5% transgenic growth on NP0 and 93.33% on NP SIM contained DNA fragments of KNAT1 gene, NPTII gene and trnL-F intergenic spacer, indicating that those plants are positive transgenic. The 35S::KNAT1 transgenes and phytohormone were independently involved in multishoot formation of P. amabilis transgenic plants. The phenotypes of plantlets were classified into six main criteria, i.e., normal shape, lobed leaves, rosette, elongated stem, cup shoot, and widened leaves. The normal type was the most abundant type of variation (±29%) in both media. Protein profile showed that all transgenic plants produced 45.8 kDa protein, and that was equivalent with molecular weight of KNAT1 protein. Taken together, all those data indicated that 35S::KNAT1 transgene was consistently integrated into the transgenic plant genome
GROWTH PERFORMANCE AND ENZYME ACTIVITIES IN CATFISH (Pangasianodon hypophthalmus) FED WITH WATER HYACINTH-BASED DIET
No full textAn alternative substitution of pollard as an imported feed ingredient is a necessity, and one of the potential ingredients is water hyacinth (Eichhornia crassipes). This study was conducted to evaluate growth performance and enzyme activity in catfish (Pangasianodon hypophthalmus). Diet with five different levels of water hyacinth substitute of pollard (0%, 25%, 50%, 75%, and 100%) were fed to catfish for 60 days. Seventy (70) catfish fry with average initial body weight of 2.45 ± 0.15 g were maintained in 100 cm × 80 cm × 60 cm aquaria. Fish fed at satiation level three times daily at 8 am, 12 pm, and 4 pm. With dietary 25% water hyacinth, growth performance and protease activity similar to 0% treatment. Feed intake, protein digestibility, feed efficiency, protein efficiency ratio, and protease and amylase enzyme activities decreased (p<0.05) in those fed with more than 25% water hyacinth. Catfish fed 25% water hyacinth showed significantly (p<0.05) higher daily growth rate, feed efficiency and protein digestibility than those with other treatments. Based on the growth performance and enzyme activity, we can conclude that the optimum dietary level of water hyacinth substitute pollard for fry catfish is 25%
INHIBITORY ACTIVITIES OF Myristica fragrans ESSENTIAL OIL ON AFLATOXIGENIC STRAINS
No full textAflatoxin B1 is a highly toxic and carcinogenic metabolite produced by aflatoxigenic strains that commonly contaminate food and agricultural commodities. This study evaluates the inhibitory effects of Myristica fragrans Houtt (nutmeg) essential oil extracted by hydrodistillation on the mycelial growth, sporulation, and aflatoxin B1 production of Aspergillus flavus IMI 242684 and Aspergillus parasiticus IMI 283883 by fumigation and contact application. An analysis of M. fragrans essential oil using the chromatography-mass spectrometry showed that its major components are safrole (42.50%), 4-terpineol (23.81%) and methyl eugenol (11.14%). At a concentration of 1000 ppm of essential oil, the mycelial growths of both Aspergillus strains were completely inhibited by vapor treatment but only reduced by about 70% by contact treatment. However, the sporulation and aflatoxin B1 production were completely inhibited by both contact and vapor treatments. Vapor treatment induced a higher level of inhibition than contact treatment. In conclusion, nutmeg essential oil is a potential biochemical agent that can help prevent contamination of stored foods and feeds
SOIL CHARACTERISTICS UNDER INTENSIFIED SHIFTING CULTIVATION FOR UPLAND RICE CULTIVATION IN UPLAND SABAL, SARAWAK, MALAYSIA
Get PDFShifting cultivation practices are regarded as the most important agricultural land-use in the marginal uplands of Sarawak for the livelihood of the rural communities. In response to various socio-economic consequences, previous practices on traditional form of shifting cultivation were altered into much sedentary farming practices. Soil productivity to sustain rice yield under current intensified forms of shifting cultivation should be of prime importance for food security among the local community at the marginal uplands of Sarawak. Therefore, this study was conducted to characterize soil properties influenced by the current intensified shifting cultivation practices at Sabal upland area, Sarawak. Along with the use of agrochemicals, shifting cultivation at Sabal area was conducted through single cultivation practices (10 to 15 years of fallow period and a cycle of rice cultivation) and multiple cultivation practices (5 to 7 years of fallow period and two cycles of rice cultivation). Before burning practices, soil pH was highly acidic (ranged from 4.28 to 4.72) in single cultivation sites; while multiple cultivation sites showed less acidic nature (soil pH ranged from 4.98 to 5.23) with relatively high secondary macronutrient contents, especially soil exchangeable Mg and Ca. No significant observation was found after burning practice in Total C and Total N of the soils at both sites. The level of soil exchangeable bases (K, Mg and Ca) and available P increased after the burning practices in single cultivation farmlands; while multiple cultivation sites showed lower to no increase in exchangeable bases and available P, partly attributed to the limited supply of nutrients from the aboveground biomass. After the harvesting of rice, soils at both sites tended to be more acidic and lower in macronutrient contents (K, Mg and Ca), primarily ascribable to crop uptake during the cultivation period. The average yield of rice in single cultivation sites and multiple cultivation sites were 721 kg/ha and 391 kg/ha, respectively. Our findings suggested that the usage of agrochemicals, particularly fertilizers in multiple cultivation sites are necessary for sustaining rice yield to restore the depleted macronutrients (especially K, Mg and Ca) after successive cultivation
SOIL MICROBIAL POPULATION AND SOIL ENZYME ACTIVITY ON PT BUKIT ASAM VARIOUS RECLAIMED LAND SITES IN SOUTH SUMATRA
No full textOpen mining activities result in decreased microbial biomass and negatively impact soil fertility. Soil microbes play a key role in the decomposition of soil organic matter and in nutrient cycling through mineralization mediated by the enzymes they produce. The purpose of this study was to analyze soil fertility levels at PT Bukit Asam’s various reclaimed land sites in Muara Enim Regency, South Sumatra, Indonesia, as determined by microbial populations and soil enzyme activity. The research was conducted using an explorative method across PT Bukit Asam’s reclaimed land sites. Soil samples from seven reclamation areas of different ages were analyzed. Our results showed that soil conditions and enzyme activity vary with reclamation age. At KTU, a 12-year-old reclaimed site, urease enzyme activity was 68.83 mg NH₄⁺·g⁻¹ dm·h⁻¹, with a microbial population of 82.64 × 10⁴ CFU·g⁻¹ soil. The highest phosphatase activity, 95.66 mg pNP·g⁻¹ dm·h⁻¹, was observed at the 9-year-old SP702 reclaimed site, with a soil pH of 5.23. Cellulase activity at the 21-year-old Udongan site was 21.51 mg GE·g⁻¹ dm·h⁻¹, with a cellulolytic microbial population of 1.9 × 10⁴ CFU·g⁻¹ soil, higher than at other reclamation sites. Invertase activity at the 15-year-old Tupak site was 24.37 mg GE·g⁻¹ dm·h⁻¹. Soil enzyme activity can serve as an indicator of soil quality and microbial activity, reflecting biochemical transformations in the soil and exhibiting high sensitivity to environmental changes
BENTHIC DIATOMS IN THE PING RIVER AND ITS TRIBUTARIES IN MAE TAENG DISTRICT, CHIANG MAI PROVINCE, THAILAND
Get PDFMae Teang District is home to many tributaries of the Ping River. Each tributary is associated with different geographical characteristics and uses. This study is the first report on benthic diatom diversity in the designated water bodies and the first comparison of benthic diatom distribution in the Ping River and its tributaries, including the Mae Hao and Mae Luang Streams in Mae Taeng District of Chiang Mai Province, Thailand. The benthic diatom distribution and physico-chemical properties were investigated in August and November 2015 at three locations in each water body. The highest abundance of benthic diatoms was found in the Ping River (143 species), followed by Mae Hao (132 species) and Mae Luang Streams (90 species). The most abundant species found in the Ping River were Planothidium lanceolatum, Nitzschia palea, Navicula cryptotenella and Seminavis strigosa. The most abundant species found in the Mae Hao Stream were Nitzschia palea, Seminavis strigosa, Surirella splendida and Sellaphora pupula. The most abundant species found in the Mae Luang Stream were Navicula cryptotenella, Diadesmis contenta, Karayevia oblongella and Achnanthes brevipes. Additionally, Amphipleura lindheimeri Grunow was identified as a newly recorded species for Thailand. This study revealed that the Ping River and Mae Hao Stream are similar bodies of water when compared with the Mae Luang Stream in terms of benthic diatom diversity and water quality. In addition, indicator species of tolerance and sensitivity to organic pollution were found. In conclusion, the areas of utilization were found to have affected the distribution of benthic diatoms in these water bodies, along with the water quality of the Ping River and its tributaries
GENOTYPIC AND PHENOTYPIC CHARACTERIZATION OF Alcaligenes javaensis JG3 POTENTIAL AS AN EFFECTIVE BIODEGRADER
Get PDFUtilization of glycerol by lipase producing bacteria offers great benefits for fat and oil waste degradation and waterwaste treatment. Nevertheless, there have been lack of reports about the availability of non-pathogenic, lipase producing bacteria, which could naturally degrade glycerol produced from the lipolysis process by lipase. This study reported a newly identified species of rhizobacteria, Alcaligenes javaensis JG3, which is not only able to produce high level of lipase, but also able to degrade glycerol molecules. Identification of strain JG3 was carried out using SEM (Scanning Electron Microscope), BD Phoenix 100 Automated Microbiology System and 16S rRNA gene analysis to determine its taxonomy status. The ability of the strain to metabolize glycerol was investigated both genotypically and phenotypically using degenerate PCR and a glycerol minimal medium. Identification test results showed that strain JG3 belongs to genus Alcaligenes, with the closest relationship with A. faecalis and A. aquatilis (96% nucleotide similarity maximum). Degenerate PCR resulted in a 248-bp sequence showing 93% similarity with glpK of Candidatus Sodalis pierantonius SOPE, a key gene involved in glycerol metabolism. In vitro glycerol utilization test result showed that Alcaligenes sp. JG3 was able to grow on glycerol aerobically, but not anaerobically. It is concluded that Alcaligenes sp. JG3 possesses genes coding for glycerol metabolism and this trait is phenotypically expressed, thus making the strain potential to be used as an effective fat and oil biodegrader