Current Pharmaceutical Biotechnology - Volume 18, Issue 15, 2017

Background: Process development involving system metabolic engineering and bioprocess engineering has become one of the major thrust for the development of therapeutic proteins or enzymes. Pichia pastoris has emerged as a prominent host for the production of therapeutic protein or enzymes. Regardless of producing high protein titers, various cellular and process level bottlenecks restrict the expression of recombinant proteins in P. pastoris. Result and Conclusion: In the present review, we have summarized the recent developments in the expression of foreign proteins in P. pastoris. Further, we have discussed various cellular engineering strategies which include codon optimization, pathway engineering, signal peptide processing, development of protease deficient strain and glyco-engineered strains for the high yield protein secretion of recombinant protein. Bioprocess development of recombinant proteins in large-scale bioreactor including medium optimization, optimum feeding strategy and co-substrate feeding in fed-batch as well as continuous cultivation have been described. The recent advances in system and synthetic biology studies including metabolic flux analysis in understanding the phenotypic characteristics of recombinant Pichia and genome editing with CRISPR-CAS system have also been summarized.

Background: It is known that sponge-associated bacteria are an attractive source of new bioactive substances with biotechnological potential. These include antimicrobials, enzymes and surfactants. However, the potential of these microorganisms remains little investigated due to the difficulty of isolating new bacterial groups that produce original bioactive metabolites and enzymes. Methods: Cultivation methods are still playing crucial functions in many studies involving bacteria isolated from sponges, and in the traditional approach for biodiscovery by screening culture collections. Results: For instance, culture media which are rich in nutrients favor the fast cultivation in comparison with slower growing bacteria, and diluted and/or poor culture media increase the possibility of growing previously uncultured bacteria. The ability to grow bacteria in culture and to characterize their secondary metabolites is a crucial approach to new biotechnology products of potential value. Many microbial biotechnology compounds used nowadays were extracted from cultured bacteria. Conclusion: This review presents and discusses some strategies to isolate and culture bacteria from sponges for biotechnological exploration. Finally, whole genome sequencing of sponge-associated bacteria is proposed as a novel strategy for biodiscovery.

Background: The later fate of a graft is highly dependent on its initial quality. Aside from that the three predominant phases during transplantation (Tx) organ retrieval, cold static preservation and reperfusion cause in a direct and indirect manner graft injury. There is complex ischemia reperfusion injury (IRI) triggered during the whole process of Tx which contributes to further damage of the graft. Methods: The today's organ preservation with commercially available solutions that all have toxic potential per se is still imperfect. Thus, improved preservation solutions are desperately needed to be able to even safely preserve grafts from extended criteria donors which are more susceptible to especially IRI. Most recently, a modified less toxic histidine-tryptophan-ketoglutarate (HTK; Custodiol®) the so called histidine-tryptophan-ketoglutarate-N (HTK-N) for both better cardioplegia and organ preservation for Tx has been developed. It is characterized as an electrolyte balanced, iron chelatorsupplemented, and amino acid-fortified organ preservation solution with replaced buffer ameliorating resistance to injury during the cold static preservation with subsequent IRI. Numerous in vitro and in vivo experiments have shown the superiority of the HTK-N solution in ROS generation, microcirculation, and subsequent inflammatory response compared with HTK. Results: According to data available to date, HTK-N has both lower cytotoxicity and higher protective potential than HTK. First clinical studies on both HTK-N for cardioplegia in cardiac surgery and for organ preservation for transplantation have been performed or are ongoing. Conclusion: In this review, the novelty and composition of HTK-N and studies investigating the potential of this new solution are focussed, after summarizing the most relevant molecular mechanisms of IRI.

Background: Agent-based models provide a formidable tool for exploring complex and emergent behaviour of biological systems as well as accurate results but with the drawback of needing a lot of computational power and time for subsequent analysis. On the other hand, equation-based models can more easily be used for complex analysis in a much shorter timescale. Methods & Objective: This paper formulates an ordinary differential equations and stochastic differential equations model to capture the behaviour of an existing agent-based model of tumour cell reprogramming and applies it to optimization of possible treatment as well as dosage sensitivity analysis. Results: For certain values of the parameter space a close match between the equation-based and agent-based models is achieved. The need for division of labour between the two approaches is explored.

Background: Fruit wines are well known for their profound health-promoting properties including both enzyme activations and inhibitions. They may act preventive in regard to diabetes melitus and other chronic diseases. Objectives: Potential α-glucosidase inhibitory activity of fruit wines made from blueberry, black chokeberry, blackberry, raspberry and sour cherry was the subject of this study. Method: In order to increase the alcohol content due to enriched extraction of total phenolics, sugar was added in the fruit pomace of the half of the examined fruit wine samples. Results: Compared with acarbose used as a positive control (IC50 = 73.78 μg/mL), all fruit wine samples exhibited higher α-glucosidase inhibitory activity. Indeed, blueberry wine samples stood out, both prepared with IC50 = 24.14 μg/mL, lyophilised extract yield 3.23% and without IC50 = 46.39 μg/mL, lyophilised extract yield 2.89% and with addition of sugar before fermentation. Chlorogenic acid predominantly contributed to α-glucosidase inhibitory activity of the blueberry, black chokeberry and sour cherry wine samples. However, ellagic acid, a potent α-glucosidase inhibitor possessing a planar structure, only slightly affected the activity of the blueberry wine samples, due to the lower concentration. In addition to this, molecular docking study of chlorogenic acid pointed out the importance of binding energy (-8.5 kcal/mol) for the inhibition of the enzyme. Conclusion: In summary, fruit wines made from blueberry should be primarily taken into consideration as a medicinal food targeting diabetes mellitus type 2 in the early stage, if additional studies would confirm their therapeutic potential for the control of postprandial hyperglycemia.