A preliminary investigation into the effects of a sex-reversal androgen, methyltestosterone, on food utilization and growth of Sarotherodon niloticus (L) fry

Three groups of Sarotherodon niloticus fry were fed for 8 weeks on diets either treated with 17- & methyltestosterone (MT), alcohol (CA), or untreated (CO). Growth rate and food utilization in the different groups were compared. Results indicate that the best growth, Feed Conversion Ratio (FCR), Protein Efficiency Ratio (PER) and Mean Growth Rate (MGR) were obtained with the MT diet. There was no significant difference (P 0.05) in growth and food utilization of the CA and CO fry, nor in the mortality rate of the 3 treatments. The androgen, methyltestosterone promotes growth and protein anabolism without producing toxic effects in S. niloticu

GROWTH AND PROTEIN CONTENT OF Ulva prolifera MAINTAINED AT DIFFERENT FLOW RATES IN INTEGRATED AQUACULTURE SYSTEM

Efforts to reduce the impact of waste improvement on degradation of water quality can be transferred by utilization of inorganic waste as a source of seaweed nutrition. This study aimed to determine the growth and protein content of Ulva prolifera maintained at different flow rates in integrated aquaculture system. 9 Yellowtail stocked with 5.095 g with an average weight of 566.11±81.51 g were kept in 540 L tank for 24 days, by water flowing at the rate of 10 L min-1. Water from the fish tank was distributed into the sediment tank and go to 6 Ulva tanks with the flow rate of 0.5, 1.0 and 1.5 L min-1. Test parameters measured were growth performance of Yellowtail, biomass of Ulva prolifera, protein content of Ulva prolifera, and total ammonia nitrogen. The measurement results showed that the biomass of fish increased to 5.408 g, then biomass of Ulva increased to 42 g, 156 g and 155 g for flow rate of 0.5 L, 1 L and 1.5 L min-1, respectively. The protein content of Ulva for all the treatments was the same (P> 0.05). A total of ammonia in the tank outlet of Ulva (0.0202 - 0.1137 mg N L-1) were smaller than those were in the inlet (0.0286 - 0.1394 mg N L-1)

Minimizing acetate formation in E. coli fermentations

Escherichia coli remains the best established production organisms in industrial biotechnology. However, during aerobic fermentation runs at high growth rates, considerable amounts of acetate are accumulated as by-product. This by-product has negative effects on growth and protein production. Over the last 20 years, substantial research efforts have been spent to reduce acetate accumulation during aerobic growth of E. coli on glucose. From the onset it was clear that this quest should not be a simple nor uncomplicated one. Simple deletion of the acetate pathway, reduced the acetate accumulation, but instead other by-products were formed. This minireview gives a clear outline of these research efforts and the outcome of them, including bioprocess level approaches and genetic approaches. Recently, the latter seems to have some promising results

Decoupling growth and protein production in CHO cells:A targeted approach

Fed-batch cultures of Chinese Hamster Ovary cells have been used to produce high quantities of biotherapeutics, particularly monoclonal antibodies. However, a growing number of next-generation biotherapeutics, such as bi-specific antibodies and fusion proteins, are difficult to express using standard fed-batch processes. Decoupling cell growth and biotherapeutic production is becoming an increasingly desired strategy for the biomanufacturing industry, especially for difficult-to-express products. Cells are grown to a high cell density in the absence of recombinant protein production (the growth phase), then expression of the recombinant protein is induced and cell proliferation halted (the production phase), usually by combining an inducible gene expression system with a proliferation control strategy. Separating the growth and production phases allows cell resources to be more efficiently directed toward either growth or production, improving growth characteristics and enhancing the production of difficult to express proteins. However, current mammalian cell proliferation control methods rely on temperature shifts and chemical agents, which interact with many non-proliferation pathways, leading to variable impacts on product quality and culture viability. Synthetic biology offers an alternative approach by strategically targeting proliferation pathways to arrest cell growth but have largely remained unused in industrial bioproduction. Due to recent developments in microbial decoupling systems and advances in available mammalian cell engineering tools, we propose that the synthetic biology approach to decoupling growth and production needs revisiting

Pengaruh Penambahan Pupuk Majemuk Npk terhadap Pertumbuhan dan Kadar Protein Jamur Tiram Putih (Pleurotus Ostreatus) sebagai Pengembangan Modul Pembelajaran Biologi Konsep Jamur (Fungi) di Kelas X SMA

The research was conducted to determine the effect of NPK complex fertilizers to the growth and protein content white oyster mushrooms (pleurotus ostreatus) on March-May 2016. The results used as module development of biology learning of concept mushrooms (fungi) in class x senior high school. The study consisted of two phases, the first effect of NPK complex fertilizers to the growth and protein content white oyster mushrooms (pleurotus ostreatus) using non factorial completely randomized design that consist 5 treatments and 3 replicatesand totally obtain 15 experimental design. It would further DMRT test if effect. The observed parameters include growth and protein content white oyster mushrooms. The second phase, developing a module with concept of mushrooms (fungi) by using ADDIE models. Based on the survey results revealed that the addition of NPK effect on all parameters observed where the best dosage with the addition of NPK 10gr / 1 kg of growing media. The results of the research used to development of modules and get valid with a mean value of 4.03

Use of the KlADH4 promoter for ethanol-dependent production of recombinant human serum albumine in Kluyveromyces lactis

KlADH4 is a gene of Kluyveromyces lactis encoding a mitochondrial alcohol dehydrogenase activity which is specifically induced by ethanol. The promoter of this gene was used for the expression of heterologous proteins in K. lactis, a very promising organism which can be used as an alternative host to Saccharomyces cerevisiae due to its good secretory properties. In this paper we report the ethanol-driven expression in K. lactis of the bacterial beta-glucuronidase and of the human serum albumin (HSA) genes under the control of the KlADH4 promoter. In particular, we studied the extracellular production of recombinant HSA (rHSA) with integrative and replicative vectors and obtained a significant increase in the amount of the protein with multicopy vectors, showing that no limitation of KlADH4 trans-acting factors occurred in the cells. By deletion analysis of the promoter, we identified an element (UASE) which is sufficient for the induction of KlADH4 by ethanol and, when inserted in the respective promoters, allows ethanol-dependent activation of other yeast genes, such as PGK and LAC4. We also analyzed the effect of medium composition on cell growth and protein secretion. A clear improvement in the production of the recombinant protein was achieved by shifting from batch cultures (0.3 g/liter) to fed-batch cultures (1 g/liter) with ethanol as the preferred carbon source

Expression, purification and characterisation of recombinant peptide:N-glycosidase F. : a thesis presented in partial fulfilment of the requirements for the degree of Master of Philosophy in Biochemistry at Massey University

PNGase F (Peptide-N4-(N-acetyl-D-glucosaminyl) asparagine amidase F) is an amidohydrolase isolated from the extracellular medium of the Gram-negative bacterium Flavobacterium meningosepticum. The 34.8-kDa enzyme catalyses the complete and intact cleavage of asparagine-linked oligosaccharide chains from their associated proteins. A T7 promoter-based E. coli expression system was developed in which PNGase F was expressed as a fusion protein with a leader sequence from the ompA gene. The hexa-histidine-tagged PNGase F was correctly processed and exported to the E. coli periplasm and had a calculated molecular weight of 36.2 kDa. A single step purification using immobilised metal affinity chromatography yielded 8 mg of pure protein per litre of culture. The sequence of the PNGase F coding region from the CDC strain 3352 of F. meningosepticum was found to differ from a published sequence from another strain of the bacterium (ATCC 33958) in 57 positions. These differences between the two strains result in eight amino acid substitutions, which are mostly conservative in nature and are on the surface of the protein. Moreover, three potential N-glycosylation sites not present in the ATCC strain 33958 were detected in CDC strain 3352. The recombinant enzyme has similar characteristics of the native enzyme with a pH optimum of 8.5 and is strongly inhibited by Ag+, Cu2+, Fe3+ ions but not by sulfhydryl-targeting agents such as DTT and NEM. This indicates inhibition by these ions is probably through interactions with a histidine residue at position 193 that may be involved in substrate recognition or catalysis. The specific activity of the native PNGase F is about four times that of the recombinant protein which may be contributed to inhibition by components of the CompleteTM protease inhibitor tablets used in the enzyme preparation or due to modifications for cloning and purification. Using a discontinuous assay and a non-labelled 11-mer ovalbumin-derived glycopeptide as substrate, a rough estimate of the Michaelis constant (Km) for the recombinant PNGase F was determined to be 2.1 μM. An intriguing observation with the activity assays was the apparent product inhibition of enzyme activity and the inhibitor may be either peptide and/or glycan components, which require further investigations into the cause of the inhibition

Whole-cell Escherichia coli lactate biosensor for monitoring mammalian cell cultures during biopharmaceutical production

Many high-value added recombinant proteins, such as therapeutic glycoproteins, are produced using mammalian cell cultures. In order to optimise the productivity of these cultures it is important to monitor cellular metabolism, for example the utilisation of nutrients and the accumulation of metabolic waste products. One metabolic waste product of interest is lactic acid (lactate), overaccumulation of which can decrease cellular growth and protein production. Current methods for the detection of lactate are limited in terms of cost, sensitivity, and robustness. Therefore, we developed a whole-cell Escherichia coli lactate biosensor based on the lldPRD operon and successfully used it to monitor lactate concentration in mammalian cell cultures. Using real samples and analytical validation we demonstrate that our biosensor can be used for absolute quantification of metabolites in complex samples with high accuracy, sensitivity and robustness. Importantly, our whole-cell biosensor was able to detect lactate at concentrations more than two orders of magnitude lower than the industry standard method, making it useful for monitoring lactate concentrations in early phase culture. Given the importance of lactate in a variety of both industrial and clinical contexts we anticipate that our whole-cell biosensor can be used to address a range of interesting biological questions. It also serves as a blueprint for how to capitalise on the wealth of genetic operons for metabolite sensing available in Nature for the development of other whole-cell biosensors