Dry Cell Biomass Research Articles

Endophyte-based fungal elicitors for enhanced production of valepotriates and sesquiterpenoids in leaf cell suspension cultures of Valeriana jatamansi Jones.

The immense therapeutic value of Valeriana jatamansi is attributed to the presence of bioactive secondary metabolites (valepotriates and sesquiterpenoids). Its over-exploitation in wild habitats resulted in extensive depletion, necessitating alternative approaches to produce its therapeutic metabolites. This study sought to assess the ability of endophytes of V. jatamansi to boost the biosynthesis of secondary metabolites in the leaf-cell suspension (LCS) culture of V. jatamansi. A total of 11 fungal endophytes were isolated from the rhizomes of V. jatamansi. Isolated endophytes were found to belong to phylum Ascomycota, Basidiomycota, and Mucoromycota. Supplementation of extracts of endophyte Phaeosphaeriaceae sp. VRzFB, Mucor griseocyanus VRzFD, Penicillium raistrickii VRzFK, and Penicillium sajarovii VRzFL in the LCS culture of V. jatamansi increased the fresh cell biomass by 19.6%-39.1% and dry cell biomass by 23.4%-37.8%. Most of the endophytes' extract could increase the content of valepotriates (26.5%-76.5% valtrate and 40.5%-77.9% acevaltrate) and sesquiterpenoids (19.9%-61.1% hydroxyl valerenic acid) in LCS culture. However, only two endophytes, Irpex lacteus VRzFI and Fusarium oxysporum VRzFF, could increase the sesquiterpenoids acetoxy valerenic acid (36.9%-55.3%). In contrast, some endophytes' extracts caused negative or no significant effect on the cell biomass and targeted metabolites. Increased secondary metabolites were corroborated with increased expression of iridoid biosynthesis genes in LCS culture. Production of H2O2 and lipid peroxidation was also varied with different endophytes indicating the modulation of cellular oxidative stress due to endophyte elicitors. The results suggest the distinct effect of different fungal endophytes-extract on LCS culture, and endophytes can serve as biotic elicitors for increasing the secondary metabolite production in plant in vitro systems.

Treatment of sewage sludge with γ‐ray irradiation for volatile fatty acids and lipid production

AbstractThe production of value‐added products from sewage sludge is considered to be one of the solutions for the sustainable management of sludge in wastewater treatment plants (WWTPs). The presence of carbon, nitrogen, and phosphorus sources has made the sewage sludge of WWTPs a valuable and low‐cost substrate for the production of fermentative products. In the current study, a process was developed for microbial lipid production from two types of sewage sludge from a WWTP in northern Isfahan: anaerobic digester inlet sludge (DIS) and anaerobic digester outlet sludge (DOS). This process was based on the release of volatile fatty acids (VFAs) from the sludge by combinations of γ‐ray irradiation, anaerobic digestion, and acidogenic fermentation followed by utilization of VFAs in a microbial process by the oleaginous yeast Cryptococcus aureus UIMC65. After γ‐ray irradiation, the acidogenic fermentation of the treated sludge released 72% of the organic matter content of the sludge with acidification efficiency of 12% leading to 0.516 g L−1 VFAs. The oleaginous fermentation of the released VFAs for 7 days was accompanied by production of 1.58 g L−1 dry cell biomass with 40% lipid content. The results of this study indicate that the sewage sludge from urban WWTP has the potential to be used for the production of microbial lipids.

Valorization of waste engine oil to mono- and di-rhamnolipid in a sustainable approach to circular bioeconomy.

This study aims to valorize waste engine oil (WEO) for synthesizing economically viable biosurfactants (rhamnolipids) to strengthen the circular bioeconomy concept. It specifically focuses on investigating the influence of key bioprocess parameters, viz. agitation and aeration rates, on enhancing rhamnolipid yield in a fed-batch fermentation mode. The methodology involves conducting experiments in a stirred tank bioreactor (3 L) using Pseudomonas aeruginosa gi |KP 163922| as the test organism. Central composite design and response surface methodology (CCD-RSM) are employed to design the experiments and analyze the effects of agitation and aeration rates on various parameters, including dry cell biomass (DCBM), surface tension, tensoactivity, and rhamnolipid yield. It is also essential to determine the mechanistic pathway of biosurfactant production followed by the strain using complex hydrophobic substrates such as WEO. The study reveals that optimal agitation and aeration rates of 200rpm and 1 Lpm result in the highest biosurfactant yield of 29.76g/L with minimal surface tension (28 mN/m). Biosurfactant characterization using FTIR, 1H NMR, and UPLC-MS/MS confirm the presence of dominant molecular ion peaks m/z 543.9 and 675.1. This suggests that the biosurfactant is a mixture of mono- and di-rhamnolipids (RhaC10C10, RhaRhaC10C12:1, RhaRhaC12:1C10). The findings present a sustainable approach for biosurfactant production in a fed-batch bioreactor. This research opens the possibility of exploring the use of pilot or large-scale bioreactors for biosurfactant production in future investigations.

Rhamnolipid production by Pseudomonas aeruginosa (SSL-4) on waste engine oil (WEO): Taguchi optimization, soil remediation, and phytotoxicity investigation

ABSTRACT Environmental concerns and rising biosurfactant demand emphasize the need for this study. The objective is to maximize rhamnolipid-biosurfactant production by Pseudomonas aeruginosa (SSL-4) utilizing waste engine oil (WEO) as the sole substrate for use in soil bioremediation and commercial production. Using an L16 Taguchi orthogonal array, a signal-to-noise ratio, and an analysis of variance (ANOVA), the effects of environmental (pH, incubation temperature) and dietary parameters (carbon source concentration, carbon/nitrogen (C/N) and carbon/phosphorus (C/P) ratio) are examined. Variations of the following parameters were made within a carefully selected range: incubation temperature of 25–40℃, pH range of 5–11, WEO concentration of 1–7% (v/v), and C/N and C/P ratios of 10–40. Response variables in this batch study include surface tension reduction (mN/m), dry cell biomass (DCBM) (g/L), and rhamnolipids yield based on substrate consumption, YP/S (g/g). Rhamnolipid was synthesized under optimal conditions, providing a yield of 21.42 g/g. The oil recovery of 74.05 ± 1.481% was achieved from oil-contaminated soil at a CMC of ∼70 mg/L. FTIR, 1H NMR, and UPLC-MS techniques were utilized for the characterization of rhamnolipids, and AAS for determining heavy metals concentration in WEO and residual waste engine oil (RWEO). The Germination Index (GI) of ∼82.55% indicated no phytotoxicity associated with synthesized rhamnolipid.

Biodiesel production from a novel renewable source through the ultrasound-assisted transesterification process, using energy efficient nanocatalyst developed from waste material

The depletion of fossil fuels created a thrust for an alternative renewable energy source, which could involve sustainable energy formation and cost-reducing catalysts. The catalyst derived from the waste material, specifically a heterogenous nanocatalyst, could economically add value to the process. In this study, a novel microbial strain, Rhodotorula mucilaginosa strain SML (RM-SML), was used as a source of oil for biodiesel production. The nanocatalyst developed from the Central Avian Research Institute – Broiler (CARIB) breed eggshell was used as a catalyst for transesterification, increasing the sustainability and economic viability of the process. RM-SML yielded 68.79 % of oil to its total dry cell biomass. The calcium carbonate-rich CARIB breed eggshell was calcinated in this study to synthesize a highly dynamic heterogeneous CARIB breed eggshell nanocatalyst (CBESNC). The calcination process parameters involved in the nanocatalyst synthesis were optimized using response surface methodology, yielding a maximum calcium oxide of 38.827 %. The synthesized CBESNC was characterized for its size by scanning electron microscopy imaging and its crystallographic nature by X-ray diffraction analysis. CBESNC was used as a heterogeneous catalyst in the ultrasonic-assisted transesterification of RM-SML bio-oil. The effect of the CBESNC in RM-SML bio-oil transesterification was studied and optimized using the response surface methodology, which yielded a maximum biodiesel conversion of 98.33 %. The prediction model in optimization studies was found to fit with the process and was validated experimentally. RM-SML biodiesel was studied for its physicochemical properties and found to meet American Society for Testing and Materials biodiesel standards. It was further confirmed with Gas Chromatography-Mass Spectrum analysis. The energy analysis results proved the commercialization feasibility of the study.

Concomitant strategy of wastewater treatment and biodiesel production using innate yeast cell (Rhodotorula mucilaginosa) from food industry sewerage and its energy system analysis

In many recent studies, the wastewater with high organic matter and high utilization value compounds was treated using yeast. It decreases the effluent contaminants and makes it applicable for reuse in many food industries. This present study focuses on the combined approach of treatment and biorefinery to increase the circular economy in food industries. The two primary goals of the work were to screen the potential oleaginous yeast from the food industry effluent (FIE) collected from the food flavourant producing industry and used for FIE remediation through bioaugmentation and to extract microbial oil of yeast biomass harvested after remediation. Further, the extracted microbial oil was trans-esterified to produce biodiesel. The process of transesterification was optimized for its influencing parameters. After 10 days of treatment of FIE with the yeast cell, the treatment efficiency was analyzed and found to be precise with the typical discharge value. The overall lipid content of the oleaginous yeast (Rhodotorula mucilaginosa SML) used for the FIE treatment was 67.95 w/w% of dry cell biomass. The extracted microbial oil was used for transesterification; the process was optimized through the one-variable analysis approach and response surface methodology optimization using a central composite design. The transesterification process showed maximum conversion (98%) at oil to methanol ratio - 5.0, catalyst concentration - 2.8% and time - 1.15 h. The fatty acid composition and the physicochemical characteristics were compatible with petroleum diesel, making it applicable for alternative biofuel production. Thus, this concomitant strategy has proved efficient for reducing contaminants in FIE and suggested a new sustainable source for biodiesel production. The exergy, energy and mass balance analysis of the biodiesel conversion process proved that this process is the most economically viable one to increase the circular economy of food industries.

Effect of pH and Different Fermentation Time Intervals on the Production of Single Cell Proteins (SCPs) from Potato Peels

Dried cells of microorganisms such as fungi, algae, and bacteria, known as Single-Cell Proteins (SCPs), are utilized as a source of protein supplements in animal feed or human food. These SCPs can be produced through the use of low-cost feedstocks and waste materials as sources of carbon and energy, which can be converted into biomass and concentrated proteins. Objective: To optimize the yield and growth of dry cell biomass through the manipulation of fermentation conditions. Methods: A batch fermentation process was used to produce dry cell biomass from a microorganism. Different pH values, fermentation times, and reactor configurations were tested, and the resulting biomass was analyzed for its protein content. Results: The maximum yield of dry cell biomass was achieved at pH 4.5, with a yield of 1.951 g/100 ml. The maximum dry biomass was achieved after 72 hours of fermentation, with a yield of 2.824 g/100 ml. The maximum yield of dry biomass was achieved with an Airlift fermenter at an aeration rate of 1.0 vvm and a temperature of 35°C for 72 hours, resulting in a yield of 5.452 g/L. The protein content of the dried cell biomass was found to be in the range of 45-55%. Conclusions: This study demonstrates that the yield and growth of dry cell biomass can be optimized by controlling the fermentation conditions, specifically pH, fermentation time, and reactor configuration. These findings may have implications for the industrial-scale production of dry cell biomass, as they offer insight into how to maximize yield and protein content.

The Hypoglycemic and Hypocholesterolemic Activity of Dioscorea deltoidea, Tribulus terrestris and Panax japonicus Cell Culture Biomass in Rats with High-Fat Diet-Induced Obesity.

Obesity, and its consequences for human health, is a huge and complicated problem that has no simple solution. The constant search for natural and safe compounds with systemic action that can be used for obesity prophylactics and treatment is hampered by the limited availability and variable quality of biomass of wild medicinal plants. Plant cell biotechnology is an alternative approach for the sustainable production of vegetative biomass or individual phytochemicals with high therapeutic potential. In this study, the suspension cell biomass of the medicinal plants, Dioscorea deltoidea Wall., Tribulus terrestris L., and Panax japonicus (T. Nees) C.A. Mey, produced in 20 L and 630 L bioreactors, were tested for therapeutic effects in rat models with alimentary-induced obesity. Three-month intake of water infusions of dry cell biomass (100 mg/g body weight) against the background of a hypercaloric diet reduced weight gain and the proportion of fat mass in the obese animals. In addition, cell biomass preparation reduced the intracellular dehydration and balanced the amounts of intra- and extracellular fluids in the body as determined by bioimpedance spectroscopy. A significant decrease in the glucose and cholesterol levels in the blood was also observed as a result of cell biomass administration for all species. Hypocholesterolemic activity reduced in the line P. japonicus > D. deltoidea > T. terrestris/liraglutide > intact group > control group. By the sum of parameters tested, the cell culture of D. deltoidea was considered the most effective in mitigating diet-induced obesity, with positive effects sometimes exceeding those of the reference drug liraglutide. A safety assessment of D. deltoidea cell phytopreparation showed no toxic effect on the reproductive function of the animals and their offspring. These results support the potential application of the biotechnologically produced cell biomass of medicinal plant species as safe and effective natural remedies for the treatment of obesity and related complications, particularly for the long-term treatment and during pregnancy and lactation periods when conventional treatment is often contraindicated.

Influence of different Carbon and Nitrogen Sources on the Production of Single Cell Biomass from Potato Peels

Potato peel can be converted into various value-added compounds, such as enzymes, bio sorbents, biohydrogen, and biogas. Objective: To evaluate the influence of different Carbon and Nitrogen Sources on the Production of Single Cell Biomass from potato peels. Methods: The process of fermentation was carried out in mix broth with different concentrations of carbon, nitrogen, and different nitrogen sources to determine the effect of these factors on the production of SCP. Results: Maximum yield of dry cell biomass (0.251 and 0.245 g/100 ml) was achieved with organic nitrogen source peptone and inorganic nitrogen source ammonium sulphate, respectively. Ammonium sulphate is more suitable to use as peptone is expensive organic nitrogen source. Next optimization of nitrogen concentration was done with ammonium sulphate with different concentrations and best yield (0.190 g/100 ml) was obtained with 1.5% nitrogen concentration. Conclusions: In conclusion, the study suggests that ammonium sulphate is a more suitable nitrogen source than peptone for maximizing the yield of dry cell biomass. Additionally, optimization of nitrogen concentration with ammonium sulphate showed that a 1.5% concentration is the best for achieving the highest yield. These findings have important implications for improving the efficiency and cost-effectiveness of industrial-scale production of dry cell biomass

Conversion of Potato Peels into Single Cell Protein

The economic expansion in developing countries can be achieved by converting their low cost industrial and agricultural wastes into more valuable resultants with the help of emerging scientific approaches. Objective: to produce single cell protein from microorganism (fungus) through the process of submerged fermentation utilizing the agro-industrial waste (potato peel) as substrate. Methods: Four broths (control, glucose broth, potato peel broth and mix broth) were prepared. The maximum dry cell biomass (0.523 g/100 ml) was obtained with mix broth which was unitized for further research. All the broths were supplemented with potassium dihydrogen phosphate, magnesium sulphate, sodium chloride, and yeast extract. Result: The growth of fungal biomass in stirred tank and bubble column fermenter was compared and optimum yield was obtained with bubble column fermenter (5.45 g/100ml). This bioconversion will not only supply protein rich food but also help in control of environmental pollution. Conclusion: It is concluded that potato peels can be an attractive substrate for the production of single cell protein as they are good source of sugar and other nutrients required for the support of microorganisms

HBsAg Production in Methanol Controlled <i>P. pastoris</i> GS115 Mut<sup>S</sup> Bioreactor Process

When producing recombinant proteins with Pichia pastoris, cultivation parameters, such as induction temperature, dissolved oxygen level and residual methanol concentration play a crucial role in product biosynthesis and subsequent purification, therefore to maximize protein yields, the optimization of these parameters is imperative. Two different Pichia pastoris cultivation strategies for HBsAg VLP production in a 5 L stirred-tank bioreactor and the influence of different cultivation parameters on product yield were investigated. Residual methanol concentrations were controlled at low (>0.01 g/L), medium (1.5-2.0 g/L) and high (5.0-6.0 g/L) levels using a PI-based feed rate control algorithm based on the online methanol sensor signal. Product was purified using a novel and rapid purification method including steps of ammonium sulfate precipitation, size-exclusion chromatography and hydrophobic interaction chromatography. Employing an in-situ methanol sensor probe, the PI-based methanol feed rate control algorithm provided residual methanol concentration control with an average deviation of ±0.4 g/L from set-point value. Employing a cultivation protocol with an increased methanol concentration controlled at 6.0 g/L and a reduced DO level below 10 %, resulting in a final dry cell biomass concentration of 140 g/L and purified HBsAg VLPs yield of 186 mg/L. Developed purification method proved advantageous to other described methods, as it did not include time consuming extraction and centrifugation steps.

Isolation, characterization and fatty acid analysis of Gilbertella persicaria DSR1: A potential new source of high value single-cell oil

Oleaginous fungi accumulate a high amount of lipids in their dry biomass and have attracted more attention, due to their broad potential in biotechnological applications. The present study aimed to isolate and evaluate efficient oleaginous endophytic fungi from selected plants, followed by optimizing the potential strain's growth parameters. A total of 51 morphologically distinct fungal isolates were isolated and examined for their oleaginous character. From the preliminary screening and fermentation assay, 13 fungal isolates were identified based on their high lipid with biomass or polyunsaturated fatty acids in their fatty acid profile. During our screening process, the fungal isolate identified as Gilbertella persicaria DSR1 was found to have desirable features, such as the highest cell dry biomass (12.7 g L−1) and lipid content (34.5% of biomass) with 7% γ-linolenic acid (GLA) of total fatty acids. The least investigated isolated oleaginous strain DSR1 was subjected to optimization of various growth parameters for exploiting its full lipid accumulation potential. Under optimized conditions in the fermentor, the strain DSR1 produced 14 ± 0.3 g L−1 dry cell biomass with 42 ± 1.4% total lipid content. The major fatty acid composition of lipid confirmed by GC analysis was palmitic acid (14.7%), stearic acid (10.6%), oleic acid (37.4%), linoleic acid (20.6%), γ-linolenic acid (13.4%). This is the first report showing the oleaginous nature of G. persicaria and this isolate may be further exploited as a potential candidate for biodiesel and GLA production in larger-scale applications.

Determination of content of indole alkaloids in cell biomass of Rauwolfia serpentina Benth. ex Kurz tissue culture

Cardiovascular diseases are the most common human diseases, hence, the production of cardiological (in particular, anti-arrhythmic) medications from the natural sources is an ever-actual task. Rauwolfia serpentina Benth. is a tropical fruticose plant that is able to produce and concentrate indole alkaloids, especially ajmaline and its derivatives, which are the most effective medications against ventricular arrhythmia with low side effects.
 Aim of the study. Determination of the qualitative and quantitative content of indole alkaloids in cell biomass of Rauwolfia serpentina tissue culture, obtained by the prolonged in vitro growth.
 Materials and methods. Object: cell biomass of Rauwolfia serpentina tissue culture (K-27 strain), obtained by methods of long-term cell selection in vitro. Alkaloids content determination: TSQ Vantage LC-MS (ThermoFischer Scientific).
 Results. 20 indole alkaloids are found in cell biomass of Rauwolfia serpentina tissue culture (K-27 strain). The highest content is registered for ajmaline and its derivatives (0.690 % mass. for ajmaline). The contents of reserpine and yohimbine were found to be as low as 0.009 % and 0.020 %, respectively.
 Conclusions. It is established that the content of indole alkaloids is higher in K-27 strain in comparison to natural plant and is stable over more than 30 years of its growth. Total alkaloids content was found to be 2.8 % of dry cell biomass, and total ajmaline-type alkaloids content (including ajmaline) was found to be 1.6 % of dry cell biomass. In contrast, the total alkaloid contents in the natural plant material is reported to be in the range of 0.8–1.3 %.

Production of Poly(3-hydroxybutyrate) (P(3HB)) from Different Agroindustry Byproducts by Bacillus megaterium

The use of plastics, replacing materials such as paper and glass, has become a staple of modern society. A possible alternative is the production of biopolymers, in which case polyhydroxyalkanoates (PHAs) tend to be the most studied class. Among the PHAs, poly(3-hydroxybutyrate) (P(3HB)) is one of the most studied. Bacillus megaterium can utilize a wide range of carbon sources to produce P(3HB) and display high resistance to osmotic pressure and temperature. There are few studies regarding the viability of confectionery wastewater (CWW) and rice parboiling water (RPW) in PHA production; however, data suggests they might be successfully used as culture media for microorganisms. Cultures of B. megaterium were conducted under a 22-factorial design of experiments with different agitation and airflow conditions using mineral medium added with CWW and RPW. Under maximized conditions, it was possible to obtain 7.55 g/L of dry cell biomass, with 50.1% P(3HB) content (3.78 g/L). Kinetic parameters of the maximized culture were also assessed, with the highest productivity (0.146 g/L·h) being found after 20 h of culture. Results found in the tests indicate that CWW and RPW can be used as culture media in P(3HB) production; however further studies are necessary to fully optimize the process, as well as to find alternatives to reduce the amount of residual total organic carbon (TOC) still present in the cultures.

Potential utilization of fish waste for the sustainable production of microalgae rich in renewable protein and phycocyanin-Arthrospira platensis/Spirulina

The fish processing industry generates the solid biological waste (head, trimmings, skin, viscera, scale, bone etc) based on the processing methods, which poses a serious effect on the environment. Fish waste is valorized by various treatment methods which are costly and generate the effluents with high organic load. The objective of the present study was to utilize the fish waste in the form of fish protein hydrolysate (FPH) as an organic nitrogen source for the cultivation of Spirulina instead of inorganic nitrogen. Since the inorganic nitrogen in the algal cultivation accounts for high costs and energy, in addition to the continuous discharge of unspent inorganic nitrogen causing severe environmental problems. The proposed organic nutrient could be a sustainable and environment friendly solution from both the perspective of fish waste valorization and Spirulina cultivation. The proximate and amino acid composition of FPH derived from fish waste were characterized. Inorganic nitrogen (sodium nitrate) in the conventional medium was replaced with different concentrations of FPH varying from 0.1 to 1% (v/v). The effect of various concentrations of FPH on the growth, biomass productivity, biochemical composition and pigments of Spirulina were investigated. FPH concentration of 0.5% enhanced dry cell weight (DCW), biomass productivity (Pb), protein, and phycocyanin content by 34%, 39% and 15% and 98% respectively, compared to the conventional Zarrouk medium (control). Increase in the FPH concentration decreased the in vitro digestibility of the protein. The carbohydrate content and theoretical ethanol production were 5 times higher in the 0.1% FPH concentration than that of control. Results showed that the fish waste in the form of FPH could be a potential organic nitrogen for the cultivation of Spirulina with high quality pigment. Finally, a preliminary sustainability assessment has been made to analyze the bioeconomy of the process.

Enhanced fatty acid methyl esters recovery through a simple and rapid direct transesterification of freshly harvested biomass of Chlorella vulgaris and Messastrum gracile

Conventional microalgae oil extraction applies physicochemical destruction of dry cell biomass prior to transesterification process to produce fatty acid methyl esters (FAMEs). This report presents a simple and rapid direct transesterification (DT) method for FAMEs production and fatty acid profiling of microalgae using freshly harvested biomass. Results revealed that the FAMEs recovered from Chlorella vulgaris were 50.1 and 68.3 mg with conventional oil-extraction-transesterification (OET) and DT method, respectively. While for Messastrum gracile, the FAMEs recovered, were 49.9 and 76.3 mg, respectively with OET and DT methods. This demonstrated that the DT method increased FAMEs recovery by 36.4% and 53.0% from C. vulgaris and M. gracile, respectively, as compared to OET method. Additionally, the DT method recovered a significantly higher amount of palmitic (C16:0) and stearic (C18:0) acids from both species, which indicated the important role of these fatty acids in the membranes of cells and organelles. The DT method performed very well using a small volume (5 mL) of fresh biomass coupled with a shorter reaction time (~ 15 min), thus making real-time monitoring of FAMEs and fatty acid accumulation in microalgae culture feasible.

Efficient process development for high-level production, purification, formulation, and characterization of recombinant mecasermin in Escherichia coli.

Overproduction of recombinant mecasermin was achieved by investigation of effect of three factors, temperature, inducer amount, and culture media, at three levels according to the Taguchi statistical design in Escherichia coli in a bench-scale bioreactor. In optimal conditions (induction temperature 28 °C, terrific broth with glucose (TB+G) medium, with 0.1mM IPTG as inducer) 0.84 g/L mecasermin with expression levels of 38% of total protein and 4.13 g/L final dry cell biomass was produced, that is one of the highest values of recombinant protein has been reported in the batch system. The cell disruption was done by lysozyme pretreatment with sonication to the efficient purification of mecasermin. The isolated and washed inclusion bodies were solubilized in Gdn-HCl at pH 5.4 and folded with glutathione and purified with gel filtration. The purified rhIGF-1 (mecasermin) was formulated with arginine. Mecasermin protein remained t stable at 4 °C for up to 2 years. The quantitative and qualitative control indicated that mecasermin is expressed correctly (without the initial methionine by mass spectrometry), pure (without endotoxin and other protein impurities), correct folding (FTIR, RF-HPLC), monomer form (SEC-HPLC), and active (bioactivity test). Also, the purification results revealed that expression at low temperature results in the efficient purification of the overproduced mecasermin with high quantity and quality.

Selection and characterization yeast potential from pineapple for bioethanol production using some sugar sources

Bioethanol can be produced through fermentation process of sugars based on carbohydrate biomass such as lignosellulosa by microorganism such as yeast. Yeast changes sugar as a carbon source to produce ethanol and CO2 in anaerobic condition. Pineapple as a fruit commodity that is widely cultivated in Indonesia contain high sugar and carbohydrates so it might contain yeast which has the potential in bioethanol production. This research aims to select and characterize potential yeast from pineapple for bioethanol production from some sugars. The method included fermentation test, ethanol production (measurement of reduction sugar, dry cell biomass, and ethanol contain), and molecular identification. Yeast utilize substrates as carbon source for producing cell or ethanol. Ethanol production influenced by substrates, microorganism, and total cell. The results showed that NHC3 used as selected isolate based on the degree of coloration in Oxidative Fermentative Media. The largest ethanol production was 10,63 g/L obtained from mannose where the highest value of substrate utilization efficiency was 95%. The value of yield product is 0,27 g bioethanol/g substrate and yield biomass is 0,14 g biomass/g substrate. BLAST result shows NHC3 had homology >99% with Saccharomycetales and Kodamaea ohmeri.

Characterization of a novel herbicide and antibiotic-resistant Chlorella sp. with an extensive extracellular matrix.

A herbicide and antibiotic-resistant microalgal strain, isolated from a eutrophic site at Giofyros river (Heraklion, Crete, Greece) was extensively characterized. In the presence of relatively high concentrations of common photosynthesis inhibitors (DCMU and atrazine), as well as various antibiotics (spectinomycin, kanamycin, and chloramphenicol), the green microalga was able to increase its biomass in approximately equal levels compared to the control. Despite the high concentrations of the inhibitors, photosynthetic efficiency and chlorophyll a amount per dry cell biomass were comparable to those of control cultures in almost all cases. 18S rDNA analysis showed that this microalga belongs to the Chlorella genus. Optical and electron microscopy studies revealed the presence of an extensive extracellular matrix (EM) that surrounds the cells and plays an important role in colony formation and cell-cell interactions. Fourier transform infrared spectroscopy provided evidence that the EM consists of a polysaccharide. This matrix could be separated from the cells with a simple centrifugation. Depending on growth conditions, the dry cell biomass of this Chlorella strain was found to contain 35-39% proteins and 27-42% carbohydrates. The results of this study have demonstrated that the EM plays a protective role for cell homeostasis maintenance against the various chemical agents. This green microalga is a suitable candidate for further studies regarding sustainable biomass production in waste waters for a series of applications.

Biodiesel Production by Lipids From Indonesian strain of Microalgae Chlorella vulgaris

AbstractThe fatty acid methyl ester (FAME) production fromChlorella vulgarishas been studied by sequential investigation such as microalgae culturing, lipid extraction, and lipid conversion to FAME. TheC. vulgariscould grow well in the BG-11 medium and had a doubling time 3.7 days for its growth using inocula 16% (v/v). The optimum of dry cell biomass as 11.6 g/L was obtained after the microalgae culture harvested for 6 days. Lipid extraction from the biomass was carried out in various solvents and ultrasonication power, resulted lipid as 31% (w/w) when extracted with a mixed solvent of n-hexane-ethanol in ratio 1:1 and ultrasonication treatment at power 25 kHz/270W for 30 min. The lipid then converted to FAME through transesterification reaction with methanol using H2SO4catalyst at 45ºC for 2 h, and resulted FAME with area 32.26% in GC-MS analysis. The area was corresponded to FAME output as 13.68% (w/w). Fatty acid profiles of FAME obtained from GC-MS analysis showed the major peaks of fatty acids found inChlorella vulgariswere palmitic acid (C16:0), stearic acid (C18:0) and margaric acid (C17:0), and nonadecanoic acid (C19:0). Optimization of the transesterification reaction will be developed in future to improve the FAME product.