Revista de Bioprocessamento e Biotécnicas

Statistical experimental design was employed for the improvement of citric acid production from Madhuca indica through submerged fermentation process using mutant fungi Aspergillus niger MTCC 282. Efficient production of citric acid by mutant Aspergillus niger MTCC 282 grown on a sugar rich byproduct requires the supplementation of the optimized quantities of nutrients. Optimization of chemical parameters for the production of citric acid was done by Box-Behnken design. Box-Behnken design was used to statistically compare different combinations of four different nutrients, namely Ammonium sulphate ((NH₄)₂SO₄), Magnesium (Mg²⁺), Ethylene diamine tetra acetic acid (EDTA) and Potassium phosphate (KH₂PO₄), for the maximum production of citric acid. The optimum nutrient concentrations obtained using the Box-Behnken design were Ammonium sulphate ((NH₄)₂SO₄) 0.2138 g/l, Magnesium (Mg²⁺) 0.1896 g/l, Ethylene diamine tetra acetic acid (EDTA) 0.3968 g/l and Potassium phosphate (KH₂PO₄)₃ g/l. Under the optimum conditions, mutant Aspergillus niger MTCC 282 produced the maximum citric acid of 75 g/l of citric acid/ kg substrate at pH 4.

Instead of using energy to treat wastewater; it is actually feasible for one to harness energy from wastes as well as treating it using a Microbial Fuel Cell (MFC). An MFC generates electricity from sewage as well as sewage treatment in the same period. Four cells were used A, B, C and a control. The cells A, B, C all consisted of the anode and the cathode separated by a loamy-sandy soil of electricity conductivity, 160 μS at 22.8°C. The cathode and anodes were made of carbon rods obtained from A size dry cell. The anode and cathode were separated by 25 mm, 50 mm and 75 mm for cells A, B and C respectively. The control cell had no electrical components but shared the other components as those for cell A, B and C. sewage with COD of 2080 O₂ mg/l was introduced into the cell. Voltage and COD measurements were made every 24 hours and 10 days respectively to investigate performance. Laboratory measurements and recordings were made for 60 days and maximum voltages of 0.426V, 0.261V were recorded for A, B and C respectively. The COD removal efficiencies were over 90%, for B and C; over 60% for A and less than 40% for the control even after 60 days. This asserted that MFCs generated electricity as well as being waste treatment devices than natural or constructed waste treatment ponds. Results also showed that the further the anode-cathode separation, the lower the voltage that was developed owing to increase in cell internal resistance. This paper furthers the potential to generate green and clean energy by means of an MFC.

The demand for recombinant protein therapeutics is increasing worldwide and hence improvements in the overall yield of such products from bioprocess are of great interest to make them affordable. Chinese Hamster Ovary (CHO) cells are the most commonly used cell lines for large scale production of such high-quality (human-like) recombinant protein products. Typically, product is released, along other secretory proteins, by the cell into the culture media. These secreted proteins may have significant impact on cell growth, product quality & quantity during the production culture and the designing of strategies for efficient product purification. However, only few efforts have been made to date to explore these secreted proteins (the “secretome”), although significant technological advancements have been witnessed in the field of proteomics during the last two decades. Even from these, the majority of studies have identified a high proportion of intracellular- and non-secretory proteins in culture supernatants which could be possibly due to the unavailability of well-defined methodologies for sample collection & preparation for massspectrometry and/or followed data analysis using databases that contain less number of secretory proteins. As a result, secreted CHO proteins and their potential in regulation of recombinant protein production remain unexplored.

Therefore, the goal of this article is to provide an overview of the importance of secreted proteins in improving recombinant protein production from bioprocesses and to outline potential ways for their efficient investigation using proteomic approaches. This knowledge could help in increasing the overall yield from production processes.

Carbon rich industrial waste streams are interesting raw materials for biorefineries, due to their high abundance and relatively low price. However, they are a challenging habitat for microorganisms, due to extreme pH and temperature levels, as well as high abundance of inhibiting substances. Extreme conditions call for extreme microorganisms.

This contribution aims to show the potential of extremophilic bioprocesses for the generation of valuable products from industrial waste streams on the example of the pulping waste streams Spent Sulfite Liquor (SSL) and Black Liquor (BL). It provides an overview of products, which can be produced biotechnologically by extremophilic organisms and compares their performance to benchmark biotechnological processes. Furthermore it elucidates the factors to be considered for bioprocesses on industrial waste streams, thereby providing a toolset for selecting a bioprocess based on the waste stream. Finally bioprocesses are proposed for SSL and BL, two of which are already investigated in our workgroup.

In this research paper, a novel thermophilic bacteria named strain SO-13 was isolated from hot spring mud sample in Afyonkarahisar (Omer). Based on morphological and biochemical tests, 16S rRNA gene sequence analysis, G-C content and DNA-DNA hybridization analysis, the thermophilic isolate belonged to Anoxybacillus genus and it was closely related to A. flavithermus. The effects of different solid state fermentation conditions such as different substrate, incubation time, temperature, pH and surfactants on α-amylase production were experimented. In addition to these, different parameters such as temperature and temperature stability, pH and pH stability, detergents and surfactants, different starches and metal ions on effect of partially purified enzyme characterization were examined. The optimum temperature and pH of thermostable α-amylase was 80°C and 7.0, respectively. Thermostable α-amylase hydrolyzed the 76% and 87% of soluble starch content in red and green apple juice at 80°C in 30 min.

In the present study, efforts have been made to optimize the three process variables i.e., incubation time, temperature of separation and hypochlorite concentration for enhanced polyhydroxybutyrate (PHB) recovery from Alcaligenes cells which may serve as precursor for bio-plastic production. Screening of bio-plastic (PHB) producing microorganism was done by TEM (Transmission electron microscopy). Initially, three recovery methods were applied to achieve efficient PHB recovery which included; Alkali treatment, ATPS (Aquas two phase separation (PEG 6000)/ KH₂PO₄) and chloroform-hypochlorite dispersion (1:1, v/v). Maximum PHB recovery of 95 ± 0.5% with 97.0 ± 0.29% purity was obtained by dispersion method. In order to enhance the PHB recovery further, dispersion process was optimized using design expert (DX 8.0.6) software. PHB recovered under optimized physical condition comprising: incubation temperature 37°C, incubation time 28 h and hypochlorite concentration of 30.0, gave maximum PHB recovery of 98.2 ± 0.05% against the predicted yield of 99.0 ± 0.05% with 99.0% purity. Characterization of recovered polymer as PHB was done by FTIR (Fourier transform infrared microscopy) and NMR (Nuclear magnetic resonance spectroscopy).

Camelina sativa oil is considered a promising feedstock for biodiesel production. Response Surface Methodology (RSM) was used to optimize camelina biodiesel production by an alkali-catalyzed transesterification process. The effects of independent factors (temperature, time, molar ratio of methanol/oil, and catalyst concentration) on dependent variables (product yield and fatty acid methyl ester (FAME) yield), was investigated. Mathematical regression models were developed for prediction of the biodiesel product yield and FAME yield. The camelina biodiesel product yield (97%) and FAME yield (98.9%) were achieved at the optimal reaction conditions of 38.7°C reaction temperature, 40 min reaction time, 7.7 molar ratio of methanol/oil, and 1.5 wt.% catalyst concentration.

Large-scale manufacturing of soybean proteins results in huge volume of “wastewater” which contains substantial amount of β-amylase, and the recovery of β-amylase has potential high value. In order to evaluate the feasibility and effect of novel hybrid Ultrafiltration (UF) method against the normal method, the pretreated effluent was concentrated by a low molecular weight cut off (MWCO) 3 kDa UF membrane firstly, terminated at Volume Concentration Ratio (VCR) of ca.7. To this UF retentate was then precipitated by adding 1.2M (NH₄)₂SO₄ to remove other proteins. The supernatant obtained following centrifugation was purified through a further higher 30 kDa MWCO UF membrane, which ended at VCR of ca.10. The prepared was purified 4.8 fold, with an enzyme activity concentration ratio of 61, and is associated with 74% combined recovery for the enzyme activity, giving a final specific activity of 14 U/mg (674 U/mL), of which enzyme activity is fully enough for the industrial applications. Preliminary data of this research indicate that this could be an effective method for treating kinds of related protein wastewaters.