scholarly journals THE KINETICS BOTH OF GROWTH AND METABOLITE PRODUCTION OF X.CAMPESTRIS USING OF 4% LIQUID SUGAR SUBSTRATE FROM CASSAVA HYDROLISATE

2017 ◽  
Vol 6 (1) ◽  
pp. 45-49
Author(s):  
Nancy Siti Djenar ◽  
Edi Wahyu Sri Mulyono

X. campestris is aerobic bacteria producing extracellular biopolymers (EPS, extracellular polysaccharide) known as xanthan gum. To determine the technology and the process conditions appropriate to the formation of this product, therefore the understanding of both the kinetics of growth and metabolite production of bacteria is needed. In this research, to assess the growth of X. campestris using the method of calculation of dry cell weight. For determining the kinetics of production of metabolite used substrates of 4% liquid sugar from cassava starch hydrolysate. From this research was showed that X. campestris maximum growth in NB medium obtained in about 58thhour, at the growth rate of about 0.04 g / hour, stationary phase obtained at the 60th hour with a maximum dry cell weight of 2.7688 g/L and specific growth rate (?) of X. campestris amounted to 0.043 hour-1. Based on the kinetic curves both on growth and its metabolite production, X.campestris has non-growth associated product pattern. In this case the production of xanthan gum occured after cell growth stopped then its product is a secondary metabolite with highest amount of 3.73 g / L at 102nd hour, ie the 4th day of fermentation. Overall of this research indicated that Nutrient Broth (NB) may be used for the growth of X. campestris. But based on the value of ? above, the rate of cell reproduction was still low. Liquid sugar can be used as a substrate to produce xanthan gum. However to increase its productivity, there should be an addition of other carbon or energy and nitrogen sources.

2021 ◽  
Vol 13 (4) ◽  
pp. 2267
Author(s):  
Lenin C. Kandasamy ◽  
Marcos A. Neves ◽  
Mikihide Demura ◽  
Mitsutoshi Nakajima

The biosequestration of CO2 using microalgae has emerged as a promising means of recycling CO2 into biomass via photosynthesis, which could be used to produce biofuels as an attractive approach to CO2 mitigation. We investigated the CO2 fixation capability of the native nonaxenic microalgal culture using a 2 L photobioreactor operated in batch mode. The cultivation was carried out at varying concentrations of total dissolved CO2 (Tco2) in the bulk media ranging from 200 to 1000 mg L−1, and the temperature and light intensities were kept constant. A maximum CO2 fixation rate was observed at 400 mg L−1 of Tco2. Characteristic growth parameters such as biomass productivity, specific growth rate, maximum biomass yield, and biochemical parameters such as carbohydrate, protein, and lipids were determined and discussed. We observed that the effect of CO2 concentration on growth and biochemical composition was quite significant. The maximum biomass productivity was 22.10 ± 0.70 mg L−1 day−1, and the rate of CO2 fixation was 28.85 ± 3.00 mg L−1 day−1 at 400 mg L−1 of Tco2. The maximum carbohydrate (8.17 ± 0.49% dry cell weight) and protein (30.41 ± 0.65%) contents were observed at 400 mg L−1, whereas the lipid content (56.00 ± 0.82% dry cell weight) was the maximum at 800 mg L−1 of Tco2 in the bulk medium.


Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 443 ◽  
Author(s):  
Mai-Lan Pham ◽  
Anh-Minh Tran ◽  
Suwapat Kittibunchakul ◽  
Tien-Thanh Nguyen ◽  
Geir Mathiesen ◽  
...  

Lysin motif (LysM) domains are found in many bacterial peptidoglycan hydrolases. They can bind non-covalently to peptidoglycan and have been employed to display heterologous proteins on the bacterial cell surface. In this study, we aimed to use a single LysM domain derived from a putative extracellular transglycosylase Lp_3014 of Lactobacillus plantarum WCFS1 to display two different lactobacillal β-galactosidases, the heterodimeric LacLM-type from Lactobacillus reuteri and the homodimeric LacZ-type from Lactobacillus delbrueckii subsp. bulgaricus, on the cell surface of different Lactobacillus spp. The β-galactosidases were fused with the LysM domain and the fusion proteins, LysM-LacLMLreu and LysM-LacZLbul, were successfully expressed in Escherichia coli and subsequently displayed on the cell surface of L. plantarum WCFS1. β-Galactosidase activities obtained for L. plantarum displaying cells were 179 and 1153 U per g dry cell weight, or the amounts of active surface-anchored β-galactosidase were 0.99 and 4.61 mg per g dry cell weight for LysM-LacLMLreu and LysM-LacZLbul, respectively. LysM-LacZLbul was also displayed on the cell surface of other Lactobacillus spp. including L. delbrueckii subsp. bulgaricus, L. casei and L. helveticus, however L. plantarum is shown to be the best among Lactobacillus spp. tested for surface display of fusion LysM-LacZLbul, both with respect to the immobilization yield as well as the amount of active surface-anchored enzyme. The immobilized fusion LysM-β-galactosidases are catalytically efficient and can be reused for several repeated rounds of lactose conversion. This approach, with the β-galactosidases being displayed on the cell surface of non-genetically modified food-grade organisms, shows potential for applications of these immobilized enzymes in the synthesis of prebiotic galacto-oligosaccharides.


Biomolecules ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 198 ◽  
Author(s):  
Manoj K. Singh ◽  
Pradeep K. Rai ◽  
Anuradha Rai ◽  
Surendra Singh ◽  
Jay Shankar Singh

The production of poly-β-hydroxybutyrate (PHB) under varying environmental conditions (pH, temperature and carbon sources) was examined in the cyanobacterium Scytonema geitleri Bharadwaja isolated from the roof-top of a building. The S. geitleri produced PHB and the production of PHB was linear with the growth of cyanobacterium. The maximum PHB production (7.12% of dry cell weight) was recorded when the cells of S. geitleri were at their stationary growth phase. The production of PHB was optimum at pH 8.5 and 30 °C, and acetate (30 mM) was the preferred carbon source.


1975 ◽  
Vol 53 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Dyson Rose ◽  
S. M. Martin

Studies on the growth of batch suspension cultures of a plant cell line, initiated from Ipomoea sp. root explants, at temperatures ranging from 15 to 34 °C are reported. Maximum growth of cultures of this cell line occurred between 25 and 32 °C, with temperature variations within this range having little effect on growth rates based on dry cell yields. Cultivation at 20 °C substantially reduced the growth rate. However, cells grown at 20 °C failed to grow on transfer to fresh medium at 20 °C. Thus cultivation at suboptimum temperatures is not a satisfactory method for routine maintenance of the suspension culture.


2016 ◽  
Vol 74 (9) ◽  
pp. 2124-2134 ◽  
Author(s):  
Matthew Dubois Frigon ◽  
Dongfang Liu

Yeast activated sludge was developed and operated at salinities of 0, 15, 30, 45, and 60 g/l NaCl. The kinetics of the various sludges degrading a wastewater with glycerol as the carbon source were determined. Inhibition due to salinity was analyzed and it was found that the limiting concentration of NaCl is 120 g/l. Salinity affects the maximum growth rate of the sludge. Reactors were exposed to shock salinity changes. Salt shocks affected maximum growth rate of the reactors but treatment was still effective. The effect of pH adjustment was investigated and it was determined that hourly adjustments of pH led to the most effective treatment outcomes. Finally, DNA of the reactors was investigated. Although Scheffersomyces spartinae (Debaryomycetaceae family) was clearly more suited to the high salinity environment than other yeast species, even at high salinity the number of species was diverse. This suggests the potential to use a number of yeast species for high salinity wastewater treatment.


2018 ◽  
Vol 5 (1) ◽  
pp. 44
Author(s):  
Hans Victor ◽  
Maelita Ramdani Moeis

Process Optimization for Endoglucanase Gene Expression Derived from Bacillus sp. RP1 by Escherichia coli BL21 (DE3)/egcABSTRACTCellulases are one of the most used enzymes in industrial processes. In an effort to increase production, industries have developed strategies such as isolating new cellulase producing strains, genetic engineering and process optimization since the last 50 years. One endoglucanase producing strain, Bacillus sp. RP1 was isolated from hot springs. The ribosome binding site and coding sequence of the endoglucanase gene (egc) from Bacillus sp. RP1 was cloned into pGEM-T Easy. The recombinant plasmid was used to transform E. coli BL21 (DE3). Cloning was followed by process optimization. Medium composition was selected using Plackett-Burman design. The medium components tested were rice hull, molasses, ammonium chloride, urea and fishmeal. Rice hull and molasses were found to be the factors most influencing enzyme activity and dry cell weight, respectively. The next step involved Box-Behnken method and response surface methodology to optimize the responses against molasses concentration, rice hull concentration and fermentation time. The concentration intervals used to test were 1%, 5.5% and 10% while the fermentation time used were 24, 36 and 48 hours. The conditions which optimized both enzyme activity and dry cell weight were 7.45% molasses, 6.45% rice hull and 39.52 hours of fermentation.Keywords: Bacillus sp. RP1, E. coli BL21 (DE3), egc, Endoglucanase, optimization ABSTRAKSelulase adalah salah satu enzim yang banyak dimanfaatkan dalam berbagai industri. Sebagai upaya untuk memenuhi kebutuhan, 50 tahun terakhir dikembangkan beberapa strategi untuk meningkatkan produksi selulase yang mencakup rekayasa genetika dan optimasi proses. Karena itu, dilakukan kloning gen egc dan RBS yang berasal dari Bacillus sp. RP1 yang diisolasi dari sumber air panas ke dalam vektor pGEM-T Easy. E. coli BL21 (DE3) ditransformasikan dengan vektor yang mengandung gen egc tersebut. Setelah kloning, optimasi proses berupa desain medium turut dilakukan untuk mengoptimalkan ekspresi gen egc. Desain medium diawali dengan seleksi komposisi medium menggunakan metode Plackett-Burman. Komponen medium yang diuji adalah kulit beras, molase, amonium klorida, urea dan tepung ikan. Kulit beras dan molase diperoleh sebagai bahan yang paling berpengaruh terhadap aktivitas enzim dan berat kering sel. Tahap selanjutnya melibatkan metode statistik Box-Behnken dan metodologi respons permukaan yang bertujuan mengoptimalkan respons aktivitas enzim dan berat kering sel terhadap konsentrasi molase, konsentrasi kulit beras dan lama fermentasi. Konsentrasi yang diuji adalah 1%, 5,5% dan 10%, sedangkan lama fermentasi yang diuji adalah 24, 36 dan 48 jam. Konsentrasi optimal molase adalah 7,45% dan konsentrasi optimal kulit beras adalah 6,45% dengan lama fermentasi optimal 39,52 jam.Kata Kunci: Bacillus sp. RP1, E. coli BL21 (DE3), egc, Endoglukanase, optimasi


The Analyst ◽  
2020 ◽  
Vol 145 (18) ◽  
pp. 6148-6161 ◽  
Author(s):  
Mayur Parekh ◽  
AbdulAziz Ali ◽  
Zulfiqur Ali ◽  
Simon Bateson ◽  
Fathi Abugchem ◽  
...  

Microbioreactor system, with inset the microbioreactor element, and an example cultivation growth profile showing dissolved oxygen, pH and dry cell weight.


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