Displaying publications 21 - 40 of 57 in total

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  1. Improved cellulase production by Botryosphaeria rhodina from OPEFB at low level moisture condition through statistical optimization
    Bahrin EK, Ibrahim MF, Abd Razak MN, Abd-Aziz S, Shah UK, Alitheen N, et al.
    Prep Biochem Biotechnol, 2012;42(2):155-70.
    PMID: 22394064 DOI: 10.1080/10826068.2011.585413
    The response surface method was applied in this study to improve cellulase production from oil palm empty fruit bunch (OPEFB) by Botryosphaeria rhodina. An experimental design based on a two-level factorial was employed to screen the significant environmental factors for cellulase production. The locally isolated fungus Botryosphaeria rhodina was cultivated on OPEFB under solid-state fermentation (SSF). From the analysis of variance (ANOVA), the initial moisture content, amount of substrate, and initial pH of nutrient supplied in the SSF system significantly influenced cellulase production. Then the optimization of the variables was done using the response surface method according to central composite design (CCD). Botryosphaeria rhodina exhibited its best performance with a high predicted value of FPase enzyme production (17.95 U/g) when the initial moisture content was at 24.32%, initial pH of nutrient was 5.96, and 3.98 g of substrate was present. The statistical optimization from actual experiment resulted in a significant increment of FPase production from 3.26 to 17.91 U/g (5.49-fold). High cellulase production at low moisture content is a very rare condition for fungi cultured in solid-state fermentation.
    Matched MeSH terms: Industrial Microbiology/methods*
  2. Fulltext Production of a solvent, detergent, and thermotolerant lipase by a newly isolated Acinetobacter sp. in submerged and solid-state fermentations
    Khoramnia A, Ebrahimpour A, Beh BK, Lai OM
    J Biomed Biotechnol, 2011;2011:702179.
    PMID: 21960739 DOI: 10.1155/2011/702179
    The lipase production ability of a newly isolated Acinetobacter sp. in submerged (SmF) and solid-state (SSF) fermentations was evaluated. The results demonstrated this strain as one of the rare bacterium, which is able to grow and produce lipase in SSF even more than SmF. Coconut oil cake as a cheap agroindustrial residue was employed as the solid substrate. The lipase production was optimized in both media using artificial neural network. Multilayer normal and full feed forward backpropagation networks were selected to build predictive models to optimize the culture parameters for lipase production in SmF and SSF systems, respectively. The produced models for both systems showed high predictive accuracy where the obtained conditions were close together. The produced enzyme was characterized as a thermotolerant lipase, although the organism was mesophile. The optimum temperature for the enzyme activity was 45°C where 63% of its activity remained at 70°C after 2 h. This lipase remained active after 24 h in a broad range of pH (6-11). The lipase demonstrated strong solvent and detergent tolerance potentials. Therefore, this inexpensive lipase production for such a potent and industrially valuable lipase is promising and of considerable commercial interest for biotechnological applications.
    Matched MeSH terms: Industrial Microbiology/methods*
  3. Fulltext Recovery of glucose from residual starch of sago hampas for bioethanol production
    Awg-Adeni DS, Bujang KB, Hassan MA, Abd-Aziz S
    Biomed Res Int, 2013;2013:935852.
    PMID: 23509813 DOI: 10.1155/2013/935852
    Lower concentration of glucose was often obtained from enzymatic hydrolysis process of agricultural residue due to complexity of the biomass structure and properties. High substrate load feed into the hydrolysis system might solve this problem but has several other drawbacks such as low rate of reaction. In the present study, we have attempted to enhance glucose recovery from agricultural waste, namely, "sago hampas," through three cycles of enzymatic hydrolysis process. The substrate load at 7% (w/v) was seen to be suitable for the hydrolysis process with respect to the gelatinization reaction as well as sufficient mixture of the suspension for saccharification process. However, this study was focused on hydrolyzing starch of sago hampas, and thus to enhance concentration of glucose from 7% substrate load would be impossible. Thus, an alternative method termed as cycles I, II, and III which involved reusing the hydrolysate for subsequent enzymatic hydrolysis process was introduced. Greater improvement of glucose concentration (138.45 g/L) and better conversion yield (52.72%) were achieved with the completion of three cycles of hydrolysis. In comparison, cycle I and cycle II had glucose concentration of 27.79 g/L and 73.00 g/L, respectively. The glucose obtained was subsequently tested as substrate for bioethanol production using commercial baker's yeast. The fermentation process produced 40.30 g/L of ethanol after 16 h, which was equivalent to 93.29% of theoretical yield based on total glucose existing in fermentation media.
    Matched MeSH terms: Industrial Microbiology/methods*
  4. Potential uses of spent mushroom substrate and its associated lignocellulosic enzymes
    Phan CW, Sabaratnam V
    Appl Microbiol Biotechnol, 2012 Nov;96(4):863-73.
    PMID: 23053096 DOI: 10.1007/s00253-012-4446-9
    Mushroom industries generate a virtually in-exhaustible supply of a co-product called spent mushroom substrate (SMS). This is the unutilised substrate and the mushroom mycelium left after harvesting of mushrooms. As the mushroom industry is steadily growing, the volume of SMS generated annually is increasing. In recent years, the mushroom industry has faced challenges in storing and disposing the SMS. The obvious solution is to explore new applications of SMS. There has been considerable discussion recently about the potentials of using SMS for production of value-added products. One of them is production of lignocellulosic enzymes such as laccase, xylanase, lignin peroxidase, cellulase and hemicellulase. This paper reviews scientific research and practical applications of SMS as a readily available and cheap source of enzymes for bioremediation, animal feed and energy feedstock.
    Matched MeSH terms: Industrial Microbiology*
  5. Production of bioethanol by direct bioconversion of oil-palm industrial effluent in a stirred-tank bioreactor
    Alam MZ, Kabbashi NA, Hussin SN
    J Ind Microbiol Biotechnol, 2009 Jun;36(6):801-8.
    PMID: 19294441 DOI: 10.1007/s10295-009-0554-7
    The purpose of this study was to evaluate the feasibility of producing bioethanol from palm-oil mill effluent generated by the oil-palm industries through direct bioconversion process. The bioethanol production was carried out through the treatment of compatible mixed cultures such as Thrichoderma harzianum, Phanerochaete chrysosporium, Mucor hiemalis, and yeast, Saccharomyces cerevisiae. Simultaneous inoculation of T. harzianum and S. cerevisiae was found to be the mixed culture that yielded the highest ethanol production (4% v/v or 31.6 g/l). Statistical optimization was carried out to determine the operating conditions of the stirred-tank bioreactor for maximum bioethanol production by a two-level fractional factorial design with a single central point. The factors involved were oxygen saturation level (pO(2)%), temperature, and pH. A polynomial regression model was developed using the experimental data including the linear, quadratic, and interaction effects. Statistical analysis showed that the maximum ethanol production of 4.6% (v/v) or 36.3 g/l was achieved at a temperature of 32 degrees C, pH of 6, and pO(2) of 30%. The results of the model validation test under the developed optimum process conditions indicated that the maximum production was increased from 4.6% (v/v) to 6.5% (v/v) or 51.3 g/l with 89.1% chemical-oxygen-demand removal.
    Matched MeSH terms: Industrial Microbiology*
  6. Kinetic and stoichiometric characterization for efficient enhanced biological phosphorus removal (EBPR) process at high temperatures
    Liau KF, Shoji T, Ong YH, Chua AS, Yeoh HK, Ho PY
    Bioprocess Biosyst Eng, 2015 Apr;38(4):729-37.
    PMID: 25381606 DOI: 10.1007/s00449-014-1313-3
    A recently reported stable and efficient EBPR system at high temperatures around 30 °C has led to characterization of kinetic and stoichiometric parameters of the Activated Sludge Model no. 2d (ASM2d). Firstly, suitable model parameters were selected by identifiability analysis. Next, the model was calibrated and validated. ASM2d was found to represent the processes well at 28 and 32 °C except in polyhyroxyalkanoate (PHA) accumulation of the latter. The values of the kinetic parameters for PHA storage (q PHA), polyphosphate storage (q PP) and growth (μ PAO) of polyphosphate-accumulating organisms (PAOs) at 28 and 32 °C were found to be much higher than those reported by previous studies. Besides, the value of the stoichiometric parameter for the requirement of polyphosphate for PHA storage (Y PO4) was found to decrease as temperature rose from 28 to 32 °C. Values of two other stoichiometric parameters, i.e. the growth yield of heterotrophic organisms (Y H) and PAOs (Y PAO), were high at both temperatures. These calibrated parameters imply that the extremely active PAOs of the study were able to store PHA, store polyphosphate and even utilize PHA for cell growth. Besides, the parameters do not follow the Arrhenius correlation due to the previously reported unique microbial clade at 28 and 32 °C, which actively performs EBPR at high temperatures.
    Matched MeSH terms: Industrial Microbiology*
  7. Influence of agitation speed on tannase production and morphology of Aspergillus niger FETL FT3 in submerged fermentation
    Darah I, Sumathi G, Jain K, Lim SH
    Appl Biochem Biotechnol, 2011 Dec;165(7-8):1682-90.
    PMID: 21947762 DOI: 10.1007/s12010-011-9387-8
    Agitation speed was found to influence the tannase production and fungal growth of Aspergillus niger FETL FT3. The optimal agitation speed was at 200 rpm which produced 1.41 U/ml tannase and 3.75 g/l of fungal growth. Lower or higher agitation speeds than 200 rpm produced lower enzyme production and fungal growth. Based on the SEM and TEM micrograph observation, there was a significant correlation between agitation speed and the morphology of the fungal mycelia. The results revealed an increase of the enzyme production with the change of the fungal growth morphology from filamentous to pelleted growth forms. However, the exposure to higher shear stress with an increasing agitation speed of the shaker also resulted in lower biomass yields as well as enzyme production.
    Matched MeSH terms: Industrial Microbiology/instrumentation; Industrial Microbiology/methods*
  8. The workability of Escherichia coli BL21 (DE3) and Pseudomonas putida KT2440 expression platforms with autodisplayed cellulases: a comparison
    Obeng EM, Brossette T, Ongkudon CM, Budiman C, Maas R, Jose J
    Appl Microbiol Biotechnol, 2018 Jun;102(11):4829-4841.
    PMID: 29675801 DOI: 10.1007/s00253-018-8987-4
    This article comparatively reports the workability of Escherichia coli BL21(DE3) and Pseudomonas putida KT2440 cell factories for the expression of three model autodisplayed cellulases (i.e., endoglucanase, BsCel5A; exoglucanase, CelK; β-glucosidase, BglA). The differentiation of the recombinant cells was restricted to their cell growth and enzyme expression/activity attributes. Comparatively, the recombinant E. coli showed higher cell growth rates but lower enzyme activities than the recombinant P. putida. However, the endo-, exoglucanase, and β-glucosidase on the surfaces of both cell factories showed activity over a broad range of pH (4-10) and temperature (30-100 °C). The pH and temperature optima were pH 6, 60 °C (BsCel5A); pH 6, 60-70 °C (CelK); and pH 6, 50 °C (BglA). Overall, the P. putida cell factory with autodisplayed enzymes demonstrated higher bioactivity and remarkable biochemical characteristics and thus was chosen for the saccharification of filter paper. A volumetric blend of the three cellulases with P. putida as the host yielded a ratio of 1:1:1.5 of endoglucanase, exoglucanase, and β-glucosidase, respectively, as the optimum blend composition for filter paper degradation. At an optical density (578 nm) of 50, the blend generated a maximum sugar yield of about 0.7 mg/ml (~ 0.08 U/g) from Whatman filter paper (Ø 6 mm, ~ 2.5 mg) within 24 h.
    Matched MeSH terms: Industrial Microbiology
  9. Effect of agitation and aeration rates on chitinase production using Trichoderma virens UKM1 in 2-l stirred tank reactor
    Abd-Aziz S, Fernandez CC, Salleh MM, Illias RM, Hassan MA
    Appl Biochem Biotechnol, 2008 Aug;150(2):193-204.
    PMID: 18633736 DOI: 10.1007/s12010-008-8140-4
    Shrimps have been a popular raw material for the burgeoning marine and food industry contributing to increasing marine waste. Shrimp waste, which is rich in organic compounds is an abundant source of chitin, a natural polymer of N-acetyl-D-glucosamine (GluNac), a reducing sugar. For this respect, chitinase-producing fungi have been extensively studied as biocontrol agents. Locally isolated Trichoderma virens UKM1 was used in this study. The effect of agitation and aeration rates using colloidal chitin as control substrate in a 2-l stirred tank reactor gave the best agitation and aeration rates at 200 rpm and 0.33 vvm with 4.1 U/l per hour and 5.97 U/l per hour of maximum volumetric chitinase activity obtained, respectively. Microscopic observations showed shear sensitivity at higher agitation rate of the above system. The oxygen uptake rate during the highest chitinase productivity obtained using sun-dried ground shrimp waste of 1.74 mg of dissolved oxygen per gram of fungal biomass per hour at the kappaL a of 8.34 per hour.
    Matched MeSH terms: Industrial Microbiology
  10. The effect of aeration, agitation and light on biohydrogen production by Rhodobacter sphaeroides NCIMB 8253
    Jaapar SZ, Kalil MS, Anuar N
    Pak J Biol Sci, 2009 Sep 15;12(18):1253-9.
    PMID: 20384278
    Photo fermentation is a biological process that can be applied for hydrogen production. The process is environmental friendly which is operated under mild conditions using renewable resources. In order to increase yield of H2 produced by Rhodobacter sphaeroides, some experimental factors that may enhance H2 production were studied. The effect of operating parameters including agitation, aeration and light on hydrogen production using R. sphaeroides NCIMB 8253 was investigated. Rhodobacter sphaeroides NCIMB 8253 was grown in 100 mL serum bottle containing growth medium with maliec acid as the sole organic carbon source. The cultures were incubated anaerobically at 30 degrees C with tungsten lamp (100 W) as the light source (3.8 klux) and argon gas was purged for maintaining anaerobic condition. The results show that maximum hydrogen produced was higher (54.37 mL) in static culture with 69.98% of H2 in the total gas compared with shake culture (11.57 mL) with 57.86% of H2. By using static culture, H2 produced was five times higher compared with non-static in both aerobic and anaerobic condition. It was found that growth and H2 production with fluorescent lamp showed better results than growth and H2 production with tungsten light.
    Matched MeSH terms: Industrial Microbiology
  11. Central composite design for optimizing istamycin production by Streptomyces tenjimariensis
    Gomaa FAM, Selim HMRM, Alshahrani MY, Aboshanab KM
    World J Microbiol Biotechnol, 2024 Sep 09;40(10):316.
    PMID: 39249607 DOI: 10.1007/s11274-024-04118-4
    Istamycins (ISMs) are 2-deoxyfortamine-containing aminoglycoside antibiotics (AGAs) produced by Streptomyces tenjimariensis ATCC 31603 with broad-spectrum bactericidal activities against most of the clinically relevant pathogens. Therefore, this study aimed to statistically optimize the environmental conditions affecting ISMs production using the central composite design (CCD). Both the effect of culture media composition and incubation time and agitation rate were studied as one factor at the time (OFAT). The results showed that both the aminoglycoside production medium and the protoplast regeneration medium gave the highest specific productivity. Results also showed that 6 days incubation time and 200 rpm agitation were optimum for their production. A CCD quadratic model of 17 runs was employed to test three key variables: initial pH, incubation temperature, and concentration of calcium carbonate. A significant statistical model was obtained including, an initial pH of 6.38, incubation temperature of 30 ˚C, and 5.3% CaCO3 concentration. This model was verified experimentally in the lab and resulted in a 31-fold increase as compared to the unoptimized conditions and a threefold increase to that generated by using the optimized culture media. To our knowledge, this is the first report about studying environmental conditions affecting ISM production as OFAT and through CCD design of the response surface methodology (RSM) employed for statistical optimization. In conclusion, the CCD design is an effective tool for optimizing ISMs at the shake flask level. However, the optimized conditions generated using the CCD model in this study should be scaled up in a fermenter for industrial production of ISMs by S. tenjimariensis ATCC 31603 considering the studied environmental conditions that significantly influence the production proces.
    Matched MeSH terms: Industrial Microbiology
  12. Optimization of Culture Medium for the Growth of Candida sp. and Blastobotrys sp. as Starter Culture in Fermentation of Cocoa Beans (Theobroma cacao) Using Response Surface Methodology (RSM)
    Mahazar NH, Zakuan Z, Norhayati H, MeorHussin AS, Rukayadi Y
    Pak J Biol Sci, 2017;20(3):154-159.
    PMID: 29023007 DOI: 10.3923/pjbs.2017.154.159
    BACKGROUND AND OBJECTIVE: Inoculation of starter culture in cocoa bean fermentation produces consistent, predictable and high quality of fermented cocoa beans. It is important to produce healthy inoculum in cocoa bean fermentation for better fermented products. Inoculum could minimize the length of the lag phase in fermentation. The purpose of this study was to optimize the component of culture medium for the maximum cultivation of Candida sp. and Blastobotrys sp.

    MATERIALS AND METHODS: Molasses and yeast extract were chosen as medium composition and Response Surface Methodology (RSM) was then employed to optimize the molasses and yeast extract.

    RESULTS: Maximum growth of Candida sp. (7.63 log CFU mL-1) and Blastobotrys sp. (8.30 log CFU mL-1) were obtained from the fermentation. Optimum culture media for the growth of Candida sp., consist of 10% (w/v) molasses and 2% (w/v) yeast extract, while for Blastobotrys sp., were 1.94% (w/v) molasses and 2% (w/v) yeast extract.

    CONCLUSION: This study shows that culture medium consists of molasses and yeast extract were able to produce maximum growth of Candida sp. and Blastobotrys sp., as a starter culture for cocoa bean fermentation.

    Matched MeSH terms: Industrial Microbiology/methods*
  13. Fulltext Microtiter miniature shaken bioreactor system as a scale-down model for process development of production of therapeutic alpha-interferon2b by recombinant Escherichia coli
    Tan JS, Abbasiliasi S, Kadkhodaei S, Tam YJ, Tang TK, Lee YY, et al.
    BMC Microbiol, 2018 01 04;18(1):3.
    PMID: 29439680 DOI: 10.1186/s12866-017-1145-9
    BACKGROUND: Demand for high-throughput bioprocessing has dramatically increased especially in the biopharmaceutical industry because the technologies are of vital importance to process optimization and media development. This can be efficiently boosted by using microtiter plate (MTP) cultivation setup embedded into an automated liquid-handling system. The objective of this study was to establish an automated microscale method for upstream and downstream bioprocessing of α-IFN2b production by recombinant Escherichia coli. The extraction performance of α-IFN2b by osmotic shock using two different systems, automated microscale platform and manual extraction in MTP was compared.

    RESULTS: The amount of α-IFN2b extracted using automated microscale platform (49.2 μg/L) was comparable to manual osmotic shock method (48.8 μg/L), but the standard deviation was 2 times lower as compared to manual osmotic shock method. Fermentation parameters in MTP involving inoculum size, agitation speed, working volume and induction profiling revealed that the fermentation conditions for the highest production of α-IFN2b (85.5 μg/L) was attained at inoculum size of 8%, working volume of 40% and agitation speed of 1000 rpm with induction at 4 h after the inoculation.

    CONCLUSION: Although the findings at MTP scale did not show perfect scalable results as compared to shake flask culture, but microscale technique development would serve as a convenient and low-cost solution in process optimization for recombinant protein.

    Matched MeSH terms: Industrial Microbiology/methods
  14. Recent advancements in high-level synthesis of the promising clinical drug, prodigiosin
    Yip CH, Yarkoni O, Ajioka J, Wan KL, Nathan S
    Appl Microbiol Biotechnol, 2019 Feb;103(4):1667-1680.
    PMID: 30637495 DOI: 10.1007/s00253-018-09611-z
    Prodigiosin, a red linear tripyrrole pigment and a member of the prodiginine family, is normally secreted by the human pathogen Serratia marcescens as a secondary metabolite. Studies on prodigiosin have received renewed attention as a result of reported immunosuppressive, antimicrobial and anticancer properties. High-level synthesis of prodigiosin and the bioengineering of strains to synthesise useful prodiginine derivatives have also been a subject of investigation. To exploit the potential use of prodigiosin as a clinical drug targeting bacteria or as a dye for textiles, high-level synthesis of prodigiosin is a prerequisite. This review presents an overview on the biosynthesis of prodigiosin from its natural host Serratia marcescens and through recombinant approaches as well as highlighting the beneficial properties of prodigiosin. We also discuss the prospect of adopting a synthetic biology approach for safe and cost-effective production of prodigiosin in a more industrially compliant surrogate host.
    Matched MeSH terms: Industrial Microbiology/methods
  15. Keratinase production and biodegradation of polluted secondary chicken feather wastes by a newly isolated multi heavy metal tolerant bacterium-Alcaligenes sp. AQ05-001
    Yusuf I, Ahmad SA, Phang LY, Syed MA, Shamaan NA, Abdul Khalil K, et al.
    J Environ Manage, 2016 Dec 01;183:182-95.
    PMID: 27591845 DOI: 10.1016/j.jenvman.2016.08.059
    Biodegradation of agricultural wastes, generated annually from poultry farms and slaughterhouses, can solve the pollution problem and at the same time yield valuable degradation products. But these wastes also constitute environmental nuisance, especially in Malaysia where their illegal disposal on heavy metal contaminated soils poses a serious biodegradation issue as feather tends to accumulate heavy metals from the surrounding environment. Further, continuous use of feather wastes as cheap biosorbent material for the removal of heavy metals from effluents has contributed to the rising amount of polluted feathers, which has necessitated the search for heavy metal-tolerant feather degrading strains. Isolation, characterization and application of a novel heavy metal-tolerant feather-degrading bacterium, identified by 16S RNA sequencing as Alcaligenes sp. AQ05-001 in degradation of heavy metal polluted recalcitrant agricultural wastes, have been reported. Physico-cultural conditions influencing its activities were studied using one-factor-at-a-time and a statistical optimisation approach. Complete degradation of 5 g/L feather was achieved with pH 8, 2% inoculum at 27 °C and incubation period of 36 h. The medium optimisation after the response surface methodology (RSM) resulted in a 10-fold increase in keratinase production (88.4 U/mL) over the initial 8.85 U/mL when supplemented with 0.5% (w/v) sucrose, 0.15% (w/v) ammonium bicarbonate, 0.3% (w/v) skim milk, and 0.01% (w/v) urea. Under optimum conditions, the bacterium was able to degrade heavy metal polluted feathers completely and produced valuable keratinase and protein-rich hydrolysates. About 83% of the feathers polluted with a mixture of highly toxic metals were degraded with high keratinase activities. The heavy metal tolerance ability of this bacterium can be harnessed not only in keratinase production but also in the bioremediation of heavy metal-polluted feather wastes.
    Matched MeSH terms: Industrial Microbiology/methods*
  16. Fulltext Optimizing culture conditions for production of intra and extracellular inulinase and invertase from Aspergillus niger ATCC 20611 by response surface methodology (RSM)
    Dinarvand M, Rezaee M, Foroughi M
    Braz J Microbiol, 2017 Jul-Sep;48(3):427-441.
    PMID: 28359854 DOI: 10.1016/j.bjm.2016.10.026
    The aim of this study was obtain a model that maximizes growth and production of inulinase and invertase by Aspergillus niger ATCC 20611, employing response surface methodology (RSM). The RSM with a five-variable and three-level central composite design (CCD) was employed to optimize the medium composition. Results showed that the experimental data could be appropriately fitted into a second-order polynomial model with a coefficient of determination (R2) more than 0.90 for all responses. This model adequately explained the data variation and represented the actual relationships between the parameters and responses. The pH and temperature value of the cultivation medium were the most significant variables and the effects of inoculum size and agitation speed were slightly lower. The intra-extracellular inulinase, invertase production and biomass content increased 10-32 fold in the optimized medium condition (pH 6.5, temperature 30°C, 6% (v/v), inoculum size and 150rpm agitation speed) by RSM compared with medium optimized through the one-factor-at-a-time method. The process development and intensification for simultaneous production of intra-extracellular inulinase (exo and endo inulinase) and invertase from A. niger could be used for industrial applications.
    Matched MeSH terms: Industrial Microbiology/methods*
  17. Fulltext Communal microaerophilic-aerobic biodegradation of Amaranth by novel NAR-2 bacterial consortium
    Chan GF, Rashid NA, Chua LS, Ab llah N, Nasiri R, Ikubar MR
    Bioresour Technol, 2012 Feb;105:48-59.
    PMID: 22182471 DOI: 10.1016/j.biortech.2011.11.094
    A novel bacterial consortium, NAR-2 which consists of Citrobacter freundii A1, Enterococcus casseliflavus C1 and Enterobacter cloacae L17 was investigated for biodegradation of Amaranth azo dye under sequential microaerophilic-aerobic condition. The NAR-2 bacterial consortium with E. casseliflavus C1 as the dominant strain enhanced the decolorization process resulting in reduction of Amaranth in 30 min. Further aerobic biodegradation, which was dominated by C. freundii A1 and E. cloacae L17, allowed biotransformation of azo reduction intermediates and mineralization via metabolic pathways including benzoyl-CoA, protocatechuate, salicylate, gentisate, catechol and cinnamic acid. The presence of autoxidation products which could be metabolized to 2-oxopentenoate was elucidated. The biodegradation mechanism of Amaranth by NAR-2 bacterial consortium was predicted to follow the steps of azo reduction, deamination, desulfonation and aromatic ring cleavage. This is for the first time the comprehensive microaerophilic-aerobic biotransformation pathways of Amaranth dye intermediates by bacterial consortium are being proposed.
    Matched MeSH terms: Industrial Microbiology/methods
  18. Fulltext Enhanced cell disruption strategy in the release of recombinant hepatitis B surface antigen from Pichia pastoris using response surface methodology
    Tam YJ, Allaudin ZN, Lila MA, Bahaman AR, Tan JS, Rezaei MA
    BMC Biotechnol, 2012 Oct 05;12:70.
    PMID: 23039947 DOI: 10.1186/1472-6750-12-70
    BACKGROUND: Cell disruption strategies by high pressure homogenizer for the release of recombinant Hepatitis B surface antigen (HBsAg) from Pichia pastoris expression cells were optimized using response surface methodology (RSM) based on the central composite design (CCD). The factors studied include number of passes, biomass concentration and pulse pressure. Polynomial models were used to correlate the above mentioned factors to project the cell disruption capability and specific protein release of HBsAg from P. pastoris cells.

    RESULTS: The proposed cell disruption strategy consisted of a number of passes set at 20 times, biomass concentration of 7.70 g/L of dry cell weight (DCW) and pulse pressure at 1,029 bar. The optimized cell disruption strategy was shown to increase cell disruption efficiency by 2-fold and 4-fold for specific protein release of HBsAg when compared to glass bead method yielding 75.68% cell disruption rate (CDR) and HBsAg concentration of 29.20 mg/L respectively.

    CONCLUSIONS: The model equation generated from RSM on cell disruption of P. pastoris was found adequate to determine the significant factors and its interactions among the process variables and the optimum conditions in releasing HBsAg when validated against a glass bead cell disruption method. The findings from the study can open up a promising strategy for better recovery of HBsAg recombinant protein during downstream processing.

    Matched MeSH terms: Industrial Microbiology/methods*
  19. Fulltext Effects of feeding and induction strategy on the production of BmR1 antigen in recombinant E. coli
    Norsyahida A, Rahmah N, Ahmad RM
    Lett Appl Microbiol, 2009 Nov;49(5):544-50.
    PMID: 19832937 DOI: 10.1111/j.1472-765X.2009.02694.x
    To investigate the effects of feeding and induction strategies on the production of BmR1 recombinant antigen.
    Matched MeSH terms: Industrial Microbiology/methods*
  20. Production of lipids containing high levels of docosahexaenoic acid by a newly isolated microalga, Aurantiochytrium sp. KRS101
    Hong WK, Rairakhwada D, Seo PS, Park SY, Hur BK, Kim CH, et al.
    Appl Biochem Biotechnol, 2011 Aug;164(8):1468-80.
    PMID: 21424706 DOI: 10.1007/s12010-011-9227-x
    In the present study, a novel oleaginous Thraustochytrid containing a high content of docosahexaenoic acid (DHA) was isolated from a mangrove ecosystem in Malaysia. The strain identified as an Aurantiochytrium sp. by 18S rRNA sequencing and named KRS101 used various carbon and nitrogen sources, indicating metabolic versatility. Optimal culture conditions, thus maximizing cell growth, and high levels of lipid and DHA production, were attained using glucose (60 g l⁻¹) as carbon source, corn steep solid (10 g l⁻¹) as nitrogen source, and sea salt (15 g l⁻¹). The highest biomass, lipid, and DHA production of KRS101 upon fed-batch fermentation were 50.2 g l⁻¹ (16.7 g l⁻¹ day⁻¹), 21.8 g l⁻¹ (44% DCW), and 8.8 g l⁻¹ (40% TFA), respectively. Similar values were obtained when a cheap substrate like molasses, rather than glucose, was used as the carbon source (DCW of 52.44 g l⁻¹, lipid and DHA levels of 20.2 and 8.83 g l⁻¹, respectively), indicating that production of microbial oils containing high levels of DHA can be produced economically when the novel strain is used.
    Matched MeSH terms: Industrial Microbiology/methods
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