Biotechnological Production Research Articles

Pelatihan Edukasi Pemanfaatan Bahan Alam Untuk Pembuatan Produk Bioteknologi Bagi Ibu PKK Bina Mufakat

The role of biotechnology is very rapid and broad in the aspect of fulfilling human needs, one of which is in the food industry. Biotechnology processes, both conventional and modern, cannot be separated from the role of microorganisms. Certain microorganisms are used in traditional food preparation through fermentation such as in the manufacture of yogurt, tape, cheese, soy sauce, yeast. Foods resulting from biotechnology that take advantage of the role of microorganisms and must pay attention to the critical point of halal. This needs to be considered so that each production process can be ensured to avoid contamination of non-halal materials. This product will later be used for Ms. PKK Bina Mufakat both for her own use and also as an entrepreneurial opportunity for the home industry. The problem of community service activities is that there is no group development in making biotechnology products, and there is no entrepreneurship development for PKK Bina Mufakat Gampong Bayeun. The method in service activities is a type of training method. The results of community service are the creation of a product that is useful and can be used as a home industry business opportunity.

Production of biosurfactants by bacteria collected in soil contaminated by diesel oil on the Antarctic Continent

Currently, the whole world strives for a sustainable development to avoid the depletion of natural resources. Therefore, the search for new biotechnological products such as biosurfactants has generated interest due to its low toxicity, biodegradability and ecological acceptability. Furthermore, biosurfactants have several applications such as emulsification, wettability, foaming, cleaning, and reduction of crude oil viscosity. The objective of this work was to identify the bacteria collected in Antarctica and evaluate their capacity to produce biosurfactants. In this study, bacteria collected in diesel contaminated soil around the Comandante Ferraz Antarctic Station were identified (Rhodococcus erythropolis, Rhizobium radiobacter, Microbacterium liquefacien, Pseudomonas libanensis and Pseudomonas veronii) and analyses were carried out to confirm whether these bacteria produce biosurfactants. Interestingly, the compounds isolated from the bacteria showed droplet propagation and reduced the surface tension of the water, which are properties of biosurfactants. Furthermore, these compounds showed carbohydrates in their molecular composition. Given these findings, these species have potential application in biotechnological areas, such as bioremediation of environments contaminated by diesel oil and in cosmetic and personal care as emulsifier. In addition, the use of diesel oil waste by bacteria as a carbon source becomes an attractive alternative because it reduces environmental contamination and has a low cost.

Biotechnological Modification of Cider Brewing Processes for the Enhanced Production of 2-Phenylethanol

Consumers of Australian cider are currently trending towards higher-quality cider products. As a result, boutique and craft cider breweries are expected to experience a period of growth over the next five years. Supporting this trend and subsequent growth is paramount to rebuilding the cider industry post-COVID-19. Many current practices and procedures, such as must clarification and biomass reduction in cider brewing, have been adapted from the beer and wine industry. While these practices are beneficial to the quality of cider and often promote the production of favourable volatile organic compounds (VOCs), the targeted enhancement of specific VOCs has not been achieved. This work investigates the specific enhancement of 2-phenylethanol (2-PE), which is known to improve the organoleptic properties of cider and provide potential health benefits through its antioxidant properties. The effect of three levels of biomass reduction (90%, 80%, and 0%) and five levels of L-phenylalanine (L-phe) saturation (0.5, 1.0, 1.5, 2.0, and 2.5 g L−1) for the enhanced production of 2-PE during cider fermentation were investigated. A high-performance liquid chromatography method was developed to accurately quantify the concentration of both 2-PE and L-phe, with a root-mean-square deviation (RSMD) of 0.41% and 1.60%, respectively. A significant increase in 2-PE production was achieved for all treatments, with 2-PE levels up to two orders of magnitude higher than respective controls. The highest 2-PE production was achieved by a moderate (80%) biomass reduction at a 2.5 g L−1 L-phe spike. Additionally, the VOC profile of several of the ciders was quantitively determined, and subsequent data underwent extensive chemometric analysis. Principle component analysis (PCA) showed that 2-PE and its derivatives (2-phenylethyl pivalate and phenylacetaldehyde) were correlated with the 80% biomass reduction treatment at the highest L-phe spike. Additionally, it was observed that several acids and alkanes were negatively correlated with the production of 2-PE and its derivatives. Additionally, hierarchical cluster analysis (HCA) showed clustering between the 80% and 90% biomass reduction treatments at several L-phe spike concentrations. However, the 0% biomass reduction treatments only showed similarity with other treatments with 0% biomass reduction. This work provides insight into the production of 2-PE during apple cider fermentation while building the foundation for more targeted biotechnological production of favourable compounds to improve cider quality.

Metabolic engineering enables Bacillus licheniformis to grow on the marine polysaccharide ulvan

BackgroundMarine algae are responsible for half of the global primary production, converting carbon dioxide into organic compounds like carbohydrates. Particularly in eutrophic waters, they can grow into massive algal blooms. This polysaccharide rich biomass represents a cheap and abundant renewable carbon source. In nature, the diverse group of polysaccharides is decomposed by highly specialized microbial catabolic systems. We elucidated the complete degradation pathway of the green algae-specific polysaccharide ulvan in previous studies using a toolbox of enzymes discovered in the marine flavobacterium Formosa agariphila and recombinantly expressed in Escherichia coli.ResultsIn this study we show that ulvan from algal biomass can be used as feedstock for a biotechnological production strain using recombinantly expressed carbohydrate-active enzymes. We demonstrate that Bacillus licheniformis is able to grow on ulvan-derived xylose-containing oligosaccharides. Comparative growth experiments with different ulvan hydrolysates and physiological proteogenomic analyses indicated that analogues of the F. agariphila ulvan lyase and an unsaturated β-glucuronylhydrolase are missing in B. licheniformis. We reveal that the heterologous expression of these two marine enzymes in B. licheniformis enables an efficient conversion of the algal polysaccharide ulvan as carbon and energy source.ConclusionOur data demonstrate the physiological capability of the industrially relevant bacterium B. licheniformis to grow on ulvan. We present a metabolic engineering strategy to enable ulvan-based biorefinery processes using this bacterial cell factory. With this study, we provide a stepping stone for the development of future bioprocesses with Bacillus using the abundant marine renewable carbon source ulvan.

XANTHAN PRODUCTION ON CRUDE GLYCEROL BY LAB-SCALE BIOREACTOR CULTIVATION OF LOCAL Xanthomonas ISOLATE

Intensive development of the global biodiesel industry has led to the generation of a large excess of crude glycerol, which is impure, and its disposal into the environment is unacceptable without previous purification. Since purification costs are high, the application of crude glycerol in biotechnological production of valueadded products represents a promising solution for a sustainable utilization of this effluent. The aim of this study was to examine xanthan biosynthesis by the Xanthomonas PL 3 strain on a medium containing crude glycerol from biodiesel production in a laboratory-scale bioreactor in order to further scale up this bioprocess. Xanthan was produced by submerged cultivation in a crude glycerol-based medium (glycerol content of 20 g/L) in a 3 L lab-scale bioreactor (working volume of 2 L), under aerobic conditions for 168 h (0-48 h: 25°C, 1 vvm and 200 rpm; 48-168 h: 30 °C, 2 vvm, and agitation rate adjusted according to the dissolved oxygen concentration which was maintained at values higher than 30%). The bioprocess was monitored by the analysis of cultivation medium samples in predetermined time intervals, and its success was estimated based on the xanthan concentration in the medium, separated biopolymer average molecular weight and degree of nutrient conversion. In the applied experimental conditions, 11.10 g/L of xanthan with the average molecular weight of 2.85·105 g/moL was biosynthesized. At the end of this bioprocess, the degree of total glycerol, nitrogen and phosphorous conversion was 62.82%, 41.54% and 24.80%, respectively. Results obtained in this study suggest that the Xanthomonas PL 3 strain has the ability to produce xanthan of good quality on cultivation media containing crude glycerol from the biodiesel industry.

Production of extracellular lipase by Enterococcus faecium E68 with olive oil waste as substrate

With green technologies, the damages caused by agro-technological wastes to the environment are eliminated. In our study, it was aimed both to prevent the harm of olive oil waste to the environment and to produce lipase enzyme, which is an important biotechnological product.. E. faecium E68 obtained from milk and dairy products was used in the production of lipase enzyme. E. faecium E68 was developed in lipase production medium containing 10% olive waste, pH6.5, at 37oC with 120 rpm agitation for 48 hours. The effect of temperature, pH metal ion, surfactant and NaCl was also determined.
 The molecular weight of the partially purified extracellular lipase enzyme was estimated to be around 19-20 kDa by SDS-PAGE. The optimum temperature was 45°C, while the enzyme exhibited appreciable thermostability retaining of activity at 55°C for 48h. The lipase was most active in the pH range of 3-11 with an optimum activity at pH 10. 1mM, Ca 2+, Mn2+, Cu2+, Ni2+, Zn2+, Mg2+ and K+ ions modulated the activity of the enzyme but inhibited by Hg2+, SDS and Triton X-100. The enzyme is halophilic and 25% NaCl salt increased the activity.
 Olive oil waste may be the preferred substrate for lipase production.

Factors Influencing the Bioavailability of Organic Molecules to Bacterial Cells-A Mini-Review.

The bioavailability of organic compounds to bacterial cells is crucial for their vital activities. This includes both compounds that are desirable to the cells (e.g., sources of energy, carbon, nitrogen, and other nutrients) and undesirable compounds that are toxic to the cells. For this reason, bioavailability is an issue of great importance in many areas of human activity that are related to bacteria, e.g., biotechnological production, bioremediation of organic pollutants, and the use of antibiotics. This article proposes a classification of factors determining bioavailability, dividing them into factors at the physicochemical level (i.e., those related to the solubility of a chemical compound and its transport in aqueous solution) and factors at the microbiological level (i.e., those related to adsorption on the cell surface and those related to transport into the cell). Awareness of the importance of and the mechanisms governing each of the factors described allows their use to change bioavailability in the desired direction.

Rapid Screening of Polyol Polyketides from Marine Dinoflagellates.

Dinoflagellate-derived polyketides are typically large molecules (>1000 Da) with complex structures, potent bioactivities, and high toxicities. Their discovery suffers three major bottlenecks: insufficient bioavailability, low-yield cultivation of producer organisms, and production of multiple highly related analogues by a single strain. Consequently, the biotechnological production of therapeutics or toxicological standards of dinoflagellate-derived polyketides is also hampered. Strategies based on sensitive and selective techniques for chemical prospection of dinoflagellate extracts could aid in overcoming these limitations, as it allows selecting the most interesting candidates for discovery and exploitation programs according to the biosynthetic potential. In this work, we assess the combination of data-dependent liquid chromatography coupled with high-resolution tandem mass spectrometry (LC–HRMS2) and molecular networking to screen polyol polyketides. To demonstrate the power of this approach, we selected dinoflagellate Amphidinium carterae since it is commonly used as a biotechnological model and produces amphidinols, a family of polyol-polyene compounds with antifungal and antimycoplasmal activity. First, we screened families of compounds with multiple hydroxyl groups by examining MS2 profiles that contain sequential neutral losses of water. Then, we clustered MS2 spectra by molecular networking to facilitate the dereplication and discovery of amphidinols. Finally, we used the MS2 fragmentation behavior of well-characterized luteophanol D as a model to propose a structural hypothesis of nine novel amphidinols. We envision that this strategy is a valuable approach to rapidly monitoring toxin production of known and unknown polyol polyketides in dinoflagellates, even in small culture volumes, and distinguishing strains according to their toxin profiles.

Screening of Local Wild Xanthomonas Species for Xanthan Production on Crude Glycerol-based Medium

In this study, the effect of cultivation time on xanthan biosynthesis by different Xanthomonas campestris and Xanthomonas euvesicatoria strains, isolated from crucifers and pepper leaves, respectively, was examined. Xanthan was produced by submerged cultivation on crude glycerol-based medium at a laboratory level under aerobic conditions at 30 °C and 150 rpm for 168 h and 240 h. Bioprocess efficacy was estimated based on the xanthan concentration in media at the end of bioprocess and its average molecular weight. According to the obtained results, Xanthomonas strains have statistically significant effect on xanthan concentration in cultivation media when biosynthesis is performed by X. euvesicatoria strains, and cultivation time has significant effect on this parameter only when bioprocess is performed by X.campestris strains. The combination of Xanthomonas strains and cultivation time has a statistically significant effect on xanthan concentration in medium for both groups of isolates. The obtained results show that all applied Xanthomonas strains and cultivation time as well as their combination have statistically significant effect on average molecular weight of xanthan produced in applied experimental conditions. It is found that X. euvesicatoria strains produce higher amount of xanthan in a shorter period of time (168 h) when compared to the X.campestris strains. Xanthan of higher average molecular weight was produced when cultivation of both groups of isolates was performed for 240 h in applied experimental conditions. Results obtained in this research suggest that X. euvesicatoria strains have the greatest potential for application in biotechnological production of xanthan on crude glycerol-based medium.

Analytical Characterization of Host Cell Proteins (HCPs)

Biotechnology products such as biopharmaceuticals, including biosimilars, are produced in living organisms or cells. A common phrase that we hear is “the process is the product.” Thus, this process of producing these products in living organisms presents several unique challenges to consider. One of those key challenges is the characterization of not only the product itself, but other impurities in the form of host cell proteins (HCPs) that may be present. To ensure that these HCPs do not have clinical implications, it is important to understand what they are. Therefore, in this column, we take a closer look at specific analytical technologies and tools to analyze these host cell proteins, with a specific focus on liquid chromatography (LC) and mass spectrometry (MS) approaches.

Policymakers Take Notice of Bioeconomy's Potential

Policymakers Take Notice of Bioeconomy's Potential

Co-composting of cattle manure with biochar and elemental sulphur and its effects on manure quality, plant biomass and microbiological characteristics of post-harvest soil.

Improvement of manure by co-composting with other materials is beneficial to the quality of the amended soil. Therefore, the manure was supplied with either biochar, elemental sulphur or both prior to fermentation in 50 L barrels for a period of eight weeks. The manure products were subsequently analyzed and used as fertilizers in a short-term pot experiment with barley fodder (Hordeum vulgare L.). The experiment was carried out under controlled conditions in a growth chamber for 12 weeks. The sulphur-enriched manure showed the lowest manure pH and highest ammonium content. The co-fermentation of biochar and sulphur led to the highest sulphur content and an abundance of ammonium-oxidizing bacteria in manure. The biochar+sulphur-enriched manure led to the highest dry aboveground plant biomass in the amended soil, whose value was 98% higher compared to the unamended control, 38% higher compared to the variant with biochar-enriched manure and 23% higher compared to the manure-amended variant. Amendment of the sulphur-enriched manure types led to the highest enzyme activities and soil respirations (basal, substrate-induced). This innovative approach to improve the quality of organic fertilizers utilizes treated agricultural waste (biochar) and a biotechnological residual product (elementary sulphur from biogas desulphurization) and hence contributes to the circular economy.

Production of benzylglucosinolate in genetically engineered carrot suspension cultures.

Glucosinolates, a group of sulfur-containing specialized metabolites of the Brassicales, have attracted a lot of interest in nutrition, medicine and agriculture due to their positive health effects and their involvement in plant defense. Their biological activities and the extensive knowledge of their biosynthesis have inspired research into development of crops with enhanced glucosinolate contents as well as their biotechnological production in homologous and heterologous systems. Here, we provide proof-of-concept for transgenic suspension cultures of carrot (Daucus carota, Apiacae) as a scalable production platform for plant specialized metabolites using benzylglucosinolate as a model. Two T-DNAs carrying in total six genes of the benzylglucosinolate biosynthesis pathway from Arabidopsis thaliana as well as NPTII and BAR as selectable markers were transferred to carrot cells by Agrobacterium tumefaciens-mediated transformation. Putative transformants selected based on their kanamycin and BASTA resistances were subjected to HPLC-MS analysis. Of 79 putative transformants, 17 produced benzylglucosinolate. T-DNA-integration was confirmed for the five best producers. Callus from these transformants was used to establish suspension cultures for quantitative analysis. When grown in 60-ml-cultures, the best transformants produced roughly 2.5 nmol (g fw)-1 benzylglucosinolate, together with up to 10 nmol (g fw)-1 desulfobenzylglucosinolate. Only one transformant produced more benzylglucosinolate than desulfobenzylglucosinolate. The concentration of sulfate in the medium was not a major limiting factor. High production seemed to be associated with poor growth and vice versa. Therefore, future research should try to optimize medium and cultivation process and to separate growth and production phase by using an inducible promoter.

Combining metabolite doping and metabolic engineering to improve 2-phenylethanol production by engineered cyanobacteria.

2-Phenylethanol (2-PE) is a rose-scented aromatic compound, with broad application in cosmetic, pharmaceutical, food and beverage industries. Many plants naturally synthesize 2-PE via Shikimate Pathway, but its extraction is expensive and low-yielding. Consequently, most 2-PE derives from chemical synthesis, which employs petroleum as feedstock and generates unwanted by products and health issues. The need for “green” processes and the increasing public demand for natural products are pushing biotechnological production systems as promising alternatives. So far, several microorganisms have been investigated and engineered for 2-PE biosynthesis, but a few studies have focused on autotrophic microorganisms. Among them, the prokaryotic cyanobacteria can represent ideal microbial factories thanks to their ability to photosynthetically convert CO2 into valuable compounds, their minimal nutritional requirements, high photosynthetic rate and the availability of genetic and bioinformatics tools. An engineered strain of Synechococcus elongatus PCC 7942 for 2-PE production, i.e., p120, was previously published elsewhere. The strain p120 expresses four heterologous genes for the complete 2-PE synthesis pathway. Here, we developed a combined approach of metabolite doping and metabolic engineering to improve the 2-PE production kinetics of the Synechococcus elongatus PCC 7942 p120 strain. Firstly, the growth and 2-PE productivity performances of the p120 recombinant strain were analyzed to highlight potential metabolic constraints. By implementing a BG11 medium doped with L-phenylalanine, we covered the metabolic burden to which the p120 strain is strongly subjected, when the 2-PE pathway expression is induced. Additionally, we further boosted the carbon flow into the Shikimate Pathway by overexpressing the native Shikimate Kinase in the Synechococcus elongatus PCC 7942 p120 strain (i.e., 2PE_aroK). The combination of these different approaches led to a 2-PE yield of 300 mg/gDW and a maximum 2-PE titer of 285 mg/L, 2.4-fold higher than that reported in literature for the p120 recombinant strain and, to our knowledge, the highest recorded for photosynthetic microorganisms, in photoautotrophic growth condition. Finally, this work provides the basis for further optimization of the process aimed at increasing 2-PE productivity and concentration, and could offer new insights about the use of cyanobacteria as appealing microbial cell factories for the synthesis of aromatic compounds.

Glucose consumption rate-dependent transcriptome profiling of Escherichia coli provides insight on performance as microbial factories

BackgroundThe modification of glucose import capacity is an engineering strategy that has been shown to improve the characteristics of Escherichia coli as a microbial factory. A reduction in glucose import capacity can have a positive effect on production strain performance, however, this is not always the case. In this study, E. coli W3110 and a group of four isogenic derivative strains, harboring single or multiple deletions of genes encoding phosphoenolpyruvate:sugar phosphotransferase system (PTS)-dependent transporters as well as non-PTS transporters were characterized by determining their transcriptomic response to reduced glucose import capacity.ResultsThese strains were grown in bioreactors with M9 mineral salts medium containing 20 g/L of glucose, where they displayed specific growth rates ranging from 0.67 to 0.27 h−1, and specific glucose consumption rates (qs) ranging from 1.78 to 0.37 g/g h. RNA-seq analysis revealed a transcriptional response consistent with carbon source limitation among all the mutant strains, involving functions related to transport and metabolism of alternate carbon sources and characterized by a decrease in genes encoding glycolytic enzymes and an increase in gluconeogenic functions. A total of 107 and 185 genes displayed positive and negative correlations with qs, respectively. Functions displaying positive correlation included energy generation, amino acid biosynthesis, and sugar import.ConclusionChanges in gene expression of E. coli strains with impaired glucose import capacity could be correlated with qs values and this allowed an inference of the physiological state of each mutant. In strains with lower qs values, a gene expression pattern is consistent with energy limitation and entry into the stationary phase. This physiological state could explain why these strains display a lower capacity to produce recombinant protein, even when they show very low rates of acetate production. The comparison of the transcriptomes of the engineered strains employed as microbial factories is an effective approach for identifying favorable phenotypes with the potential to improve the synthesis of biotechnological products.

Systematic solvent screening and selection for polyhydroxyalkanoates (PHBV) recovery from biomass

The biotechnological production of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) derived from organic waste streams by mixed microbial communities is well established at the pilot-level. However, there is limited research on the recovery of the biopolymer from the microbial biomass, while its impact on product quality and product costs is major. When applying solvent extraction, the choice of solvent has a profound influence on many aspects of the process design. This study provides a framework to perform a systematic solvent screening for PHBV extraction. First, a database was constructed of 35 solvents that were assessed according to six different selection criteria. Then, six solvents were chosen for further experimental analysis, including 1-butanol, 2-butanol, 2-ethyl hexanol (2-EH), dimethyl carbonate (DMC), methyl isobutyl ketone (MIBK), and acetone. The main findings are that the extractions with acetone and DMC obtained the highest yields (91–95%) with reasonably high purities (93–96%), where acetone had a key advantage of the possibility to use water as anti-solvent. Moreover, the results provided new insights in the mechanisms behind PHBV extraction by pointing out that at elevated temperatures the extraction efficiency is less determined by the solvent’s solubility parameters and more determined by the solvent size. Although case-specific factors play a role in the final solvent choice, we believe that this study provides a general strategy for the solvent selection process.

Strategies for Enhancing Microbial Production of 2′-Fucosyllactose, the Most Abundant Human Milk Oligosaccharide

Human milk oligosaccharides (HMOs), a group of structurally diverse unconjugated glycans in breast milk, act as important prebiotics and have plenty of unique health effects for growing infants. 2'-Fucosyllactose (2'-FL) is the most abundant HMO, accounting for approximately 30%, among approximately 200 identified HMOs with different structures. 2'-FL can be enzymatically produced by α1,2-fucosyltransferase, using GDP-l-fucose as donor and lactose as acceptor. Metabolic engineering strategies have been widely used for enhancement of GDP-l-fucose supply and microbial production of 2'-FL with high productivity. GDP-l-fucose supply can be enhanced by two main pathways, including de novo and salvage pathways. 2'-FL-producing α1,2-fucosyltransferases have widely been identified from various microorganisms. Metabolic pathways for 2'-FL synthesis can be basically constructed by enhancing GDP-l-fucose supply and introducing α1,2-fucosyltransferase. Various strategies have been attempted to enhance 2'-FL production, such as acceptor enhancement, donor enhancement, and improvement of the functional expression of α1,2-fucosyltransferase. In this review, current progress in GDP-l-fucose synthesis and bacterial α1,2-fucosyltransferases is described in detail, various metabolic engineering strategies for enhancing 2'-FL production are comprehensively reviewed, and future research focuses in biotechnological production of 2'-FL are suggested.

Contributing Factors of Anemia in Pregnancy in the Twifo Atti-Morkwa District in Ghana

The exploding global population is presenting a new challenge of providing food for further billions of people against the backdrop of the challenges of already existing hunger and malnutrition, climate change, emerging destructive crop and animal diseases, and the pressure being exerted on arable lands by several other anthropological demands. Providing food for the world in the foreseeable future, therefore, requires the revolutionization of the agricultural sector as it stands today. Agricultural biotechnology has evolved over three decades and has presented itself as a critical avenue for addressing the perennial food production insecurity situations; particularly in Africa and other food-insecure regions of the world. This study sought to review agricultural biotechnology in Africa by assessing its current state and the future prospects of the technology on the African continent. The adoption and utilization of biotechnology in Africa have been faced with serious challenges of ethical, religious, environmental contamination, and health risks issues. Adoption of biotechnology and genetically modified (GM) products have only been achieved in a few countries in Africa on a small-scale basis and under a few selected crops. Inadequate legislation, unenhanced public education, and the spread of misconceptions by anti-GM technology activists remain a strong challenge to navigate around for the smooth adoption of the technology on the African continent. Smallholder farmers in Africa also harbor serious apprehension over seed monopoly and erosion of the traditional seed quality with neo-colonial intentions by the developers of the technology. Anti-GM sentiments based on misconceptions are deeply rooted in many African countries, heightening fear of its adoption. A stronger and more elaborate public education strategy that highlights the benefits of biotechnology and assures the people of the risk levels of the technology, and further research to alleviate public anxiety is critical for the adoption of biotechnology and GM products in Africa.

Kesikli ve Sürekli Optimizasyon Kullanarak Yapay Sinir Ağları için Sistematik Girdi Seçimi Yöntemi

Selection of input variables of the empirical models has vital effect on the prediction performance, reduced overfitting and reduced computational load. Various trials and error and sequential methods in the literature to deal with input selection for artificial neural networks (ANNs). However, these methods are not considered as automatic and systematic. This study proposes a novel and efficient mixed integer nonlinear programming-based approach to handle optimal input selection and the ANN training simultaneously for classification problems. Such selection uses binary (0-1) variables to represent the presence of the input variables and trains traditional continuous network weights simultaneously. Two classification case studies are given to demonstrate the advantages by using widely used data sets and statistical measures. The first data set is related to the characterization of the type of a tumor related to breast cancer, the second data set is about predicting the type of a biotechnological product using different features, the last one is related to heart failure prediction. Results show that better test performance can be achieved with optimally selected inputs, resulting in reduced overfitting. The proposed approach delivers a significant advantage during the design and training of the ANNs and is also applicable to other empirical models.

Acid Whey Valorization for Biotechnological Lactobionic Acid Bio-production

The dairy industry is facing a problem associated with 1.6 billion tons of acid whey per year as a waste stream. The extended amount of acid whey has encouraged studies for novel approaches of acid whey utilization. The production of lactobionic acid (LBA) using dairy waste has been in rapid demand as an economically feasible and environmentally friendly approach. The composition of acid whey makes lactose conversion into LBA by Pseudomonas taetrolens complicated. Therefore, the aim of the current research was to evaluate factors (quality of whey (salts, protein concentration, pH), volume of inoculum, and cultivation time) with the purpose of increasing the suitability of acid whey for biotechnological LBA production. LBA production was performed in a 4L bioreactor, which was equipped with a pH electrode and a dissolved oxygen electrode. The whole experiment was performed at a temperature of 30 °C under 350 rpm agitation. The continuous aeration was set at 0.5 L/min. The current study presents the study of acid and sweet whey combinations in different ratios (100:0; 50:50; 60:40, 70:30, 80:20, respectively) inoculated with 10% or 30% v/v of fresh P. taetrolens inoculum reaching up to 59.9 ± 1% LBA yield during cultivation. Increasing protein and pH in a substrate slows down the lactose converting ability of P. taetrolens. Results demonstrated that increasing the acid whey amount in a substrate can affect the LBA yield, and a combination of sweet and acid whey could be a good solution for biotechnological LBA production using dairy waste. Doi: 10.28991/HEF-SP2022-01-04 Full Text: PDF