Biotechnological Production Research Articles

Growth, morphology, and formation of cinnabarin in Pycnoporus cinnabarinus in relation to different irradiation spectra

BackgroundThe demand for natural pigments in general, and for fungi-derived pigments in particular, is constantly rising. Wood-decomposing fungi represent a promising source for natural pigments and they are usually easy to cultivate in pure culture. One of them, i.e., Pycnoporus cinnabarinus, offers a highly interesting spectrum of bioactivity, partly due to the formation of the orange–red pigment cinnabarin. However, apart from a few studies addressing its diverse potential biotechnological applications, there is still a large gap of knowledge concerning the influence of light on the formation of cinnabarin. The aim of this work was to investigate the effect of different irradiations on the cinnabarin content, the growth, and the morphology of three different P. cinnabarinus strains. We used highly standardized irradiation conditions and cultivation techniques in combination with newly developed methods for the extraction and direct quantification of cinnabarin.ResultsRed, green, blue, and UV-A irradiation (mean irradiance Ee = 1.5 ± 0.18 W m−2) had considerable effects on the growth and colony appearance of all three P. cinnabarinus strains tested. The cinnabarin content determined was, thus, dependent on the irradiation wavelength applied, allowing strain-specific thresholds to be defined. Irradiation with wavelengths below this strain-specific threshold corresponded to a lower cinnabarin content, at least at the intensity applied. The orange–red pigment appeared by light microscopy as incrusted extracellular plaques present on the hyphal walls. Highly efficient vegetative propagation occurred by arthroconidia, and we observed the tendency that this asexual reproduction was (i) most frequent in the dark but (ii) never occurred under UV-A exposure.Conclusion This study highlights a differential photo-dependence of growth, morphology, and cinnabarin formation in P. cinnabarinus. This confirms that it is advisable to consider the wavelength of the light used in future biotechnological productions of natural pigments.Graphical abstract

Myocardial Infarction Following Vaccination Against COVID-19: A Systematic Review

Context: Several reports have been presented regarding the occurrence of acute myocardial infarction following vaccination against COVID-19. Objectives: The current systemic review tried to review and summarize the published evidence and documents regarding the occurrence of myocardial infarction following various types of anti-COVID-19 vaccines (AstraZeneca and Pfizer) and, finally, take steps to clarify the causes of such incidents. Methods: The relevant databases, including Medline, Web of Knowledge, Google Scholar, Scopus, and Cochrane, were comprehensively searched by the two blinded researchers for all eligible studies based on the considered keywords. Of 76 articles initially collected by database searching, 20 articles were included in the last analysis. Results: The occurrence of acute myocardial infarction was mostly related to SARS-CoV-2-based messenger RNA and viral vector vaccines. This cardiac attack occurred after the first vaccination in 74% of patients affected. The time of occurrence of myocardial infarction was also very different between different types of vaccines and varied between 15 minutes and 21 days after vaccination. Most of the myocardial infarctions that occurred after vaccination were of the ST-segment elevation type (STEMI) (23 of 28 patients). More than two-thirds of myocardial infarction cases occurred in patients who had significant cardiovascular risk profiles (hypertension, diabetes mellitus, and ischemic heart disease). Overall, 22.2% of cases suffering post-vaccination myocardial infarction died within hospitalization. Conclusions: The occurrence of myocardial infarction following the vaccination against COVID-19 is rare, and due to the fatality of this event, it is necessary to modify the biotechnological production of existing vaccines and to accurately evaluate the pathophysiology of this event.

Visual Tools for Food Safety Assessment of Biotechnological Products

Food biotechnology, a revolutionary discipline, has transformed the way we produce, process and consume our food. It has enabled the development of new methods of crop genetic improvement, the creation of functional foods with health benefits, and the optimization of fermentation and food production processes. It has also provided innovative solutions to address the global challenges of food security and sustainability, while opening up new possibilities for nutrition and human health.

A practical blockchain-based framework for anti-counterfeiting and traceability

Blockchain has features that help systems overcome the inherent limitations of traditional centralized approaches. Integrating blockchain technologies into systems to improve security, privacy, and transparency is a prominent trend. Currently, consumers are very concerned about the origin and the legitimacy of the products, so it is necessary to strengthen anti-counterfeiting and traceability in product management. Many theoretical approaches have been proposed recently. In this study, we propose a practical framework based on blockchain that supports anti-counterfeiting and traceability. Based on the proposed practical framework, we implemented a pattern as a proof-of-concept of the approach. We conduct experiments at Thu Dau Mot University, a pioneer in the production and transfer of biotechnology. The results show feasibility and good results regarding the proposed practical framework. Moreover, we also published our code base to GitHub with an open license.

CRISPR-Cas9 assisted non-homologous end joining genome editing system of Halomonas bluephagenesis for large DNA fragment deletion

BackgroundHalophiles possess several unique properties and have broad biotechnological applications including industrial biotechnology production. Halomonas spp., especially Halomonas bluephagenesis, have been engineered to produce various biopolyesters such as polyhydroxyalkanoates (PHA), some proteins, small molecular compounds, organic acids, and has the potential to become a chassis cell for the next-generation of industrial biotechnology (NGIB) owing to its simple culture, fast growth, contamination-resistant, low production cost, and high production value. An efficient genome editing system is the key for its engineering and application. However, the efficiency of the established CRISPR-Cas-homologous recombination (HR) gene editing tool for large DNA fragments was still relatively low. In this study, we firstly report a CRISPR-Cas9 gene editing system combined with a non-homologous end joining (NHEJ) repair system for efficient large DNA fragment deletion in Halomonas bluephagenesis.ResultsThree different NHEJ repair systems were selected and functionally identified in Halomonas bluephagenesis TD01. The NHEJ system from M. tuberculosis H37Rv (Mt-NHEJ) can functionally work in H. bluephagenesis TD01, resulting in base deletion of different lengths for different genes and some random base insertions. Factors affecting knockout efficiencies, such as the number and position of sgRNAs on the DNA double-strands, the Cas9 protein promoter, and the interaction between the HR and the NHEJ repair system, were further investigated. Finally, the optimized CRISPR-Cas9-NHEJ editing system was able to delete DNA fragments up to 50 kb rapidly with high efficiency of 31.3%, when three sgRNAs on the Crick/Watson/Watson DNA double-strands and the arabinose-induced promoter Para for Cas9 were used, along with the background expression of the HR repair system.ConclusionsThis was the first report of CRISPR-Cas9 gene editing system combined with a non-homologous end joining (NHEJ) repair system for efficient large DNA fragment deletion in Halomonas spp. These results not only suggest that this editing system is a powerful genome engineering tool for constructing chassis cells in Halomonas, but also extend the application of the NHEJ repair system.

Endospore production of Bacillus spp. for industrial use.

The increased occurrence of antibiotic resistance and the harmful use of pesticides are a major problem of modern times. A ban on the use of antibiotics as growth promoters in animal breeding has put a focus on the probiotics market. Probiotic food supplements are versatile and show promising results in animal and human nutrition. Chemical pesticides can be substituted by biopesticides, which are very effective against various pests in plants due to increased research. What these fields have in common is the use of spore-forming bacteria. The endospore-forming Bacillus spp. belonging to this group offer an effective solution to the aforementioned problems. Therefore, the biotechnological production of sufficient qualities of such endospores has become an innovative and financially viable field of research. In this review, the production of different Bacillus spp. endospores will be reviewed. For this purpose, the media compositions, cultivation conditions and bioprocess optimization methods of the last 20 years are presented and reflected.

Plant breeding for harmony between sustainable agriculture, the environment, and global food security: an era of genomics-assisted breeding.

Genomics-assisted breeding represents a crucial frontier in enhancing the balance between sustainable agriculture, environmental preservation, and global food security. Its precision and efficiency hold the promise of developing resilient crops, reducing resource utilization, and safeguarding biodiversity, ultimately fostering a more sustainable and secure food production system. Agriculture has been seriously threatened over the last 40years by climate changes that menace global nutrition and food security. Changes in environmental factors like drought, salt concentration, heavy rainfalls, and extremely low or high temperatures can have a detrimental effects on plant development, growth, and yield. Extreme poverty and increasing food demand necessitate the need to break the existing production barriers in several crops. The first decade of twenty-first century marks the rapid development in the discovery of new plantbreeding technologies. In contrast, in the second decade, the focus turned to extracting information from massive genomic frameworks, speculating gene-to-phenotype associations, and producing resilient crops. In this review, we will encompass the causes, effects of abiotic stresses and how they can be addressed using plantbreeding technologies. Both conventional and modern breeding technologies will be highlighted. Moreover, the challenges like the commercialization of biotechnological products faced by proponents and developers will also be accentuated. The crux of this review is to mention the available breeding technologies that can deliver crops with high nutrition and climate resilience for sustainable agriculture.

Red sacaca essential oil-loaded nanostructured lipid carriers optimized by factorial design: cytotoxicity and cellular reactive oxygen species levels.

Amazonian flora includes several species with the potential to develop pharmaceutical and biotechnological products. The essential oils from Amazonian species possess some biological properties, such as antioxidant, antibacterial, and cytotoxic activities. The essential oil of red sacaca (RSO), Croton cajucara Benth., contains metabolites characterized by antioxidant and anti-inflammatory activities. Nanostructured lipid carriers (NLC) are an advantageous alternative for the effective delivery of drugs because they can solubilize lipophilic actives and reduce their cytotoxicity. This study aimed to optimize the synthesis of RSO-loaded nanostructured lipid carriers (NLC-RSO) using a 23 factorial design and investigate their antioxidant and cytotoxic effects. The red sacaca essential oil (RSO) metabolite profile was characterized using gas chromatography coupled with a mass spectrometer (GC-MS), identifying 33 metabolites, with linalool and 7-hydroxy-calamenene as the major ones, as reported in the literature. The optimized NLC-RSO formulation had a particle size less than 100nm and a polydispersity index lower than 0.25. After characterizing NLC-RSO using Fourier-transform infrared spectroscopy, powder X-ray diffraction, zeta potential, moisture content, and wettability, in vitro cytotoxicity were performed in A549 and BEAS-2B cell lines using the resazurin metabolism assay. The data indicated a lower IC50 for RSO than for NLC-RSOs in both cell lines. Furthermore, low cytotoxicity of blank nanoparticles (blank NP) and medium chain triglycerides-loaded nanostructured lipid carriers (NLC-MCT) towards both pulmonary cell lines was noted. At a concentration of 50-100μg/mL, free RSO exhibited higher cytotoxicity than NLC-RSO, demonstrating the protective effect of this lipid carrier in reducing cytotoxicity during metabolite delivery. Similarly, free RSO showed higher 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging than NLC-RSO, also indicating this protective effect. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) intracellular reactive oxygen species (ROS) level assay did not show differences between the treatments at higher but non-cytotoxic dosages. Taken together, our results suggest that NLC-RSOs are potential RSO delivery systems for applications related to cancer treatment.

Identification and quantification of biosurfactants produced by the marine bacterium Alcanivorax borkumensis by hyphenated techniques

A novel biosurfactant was discovered to be synthesized by the marine bacterium Alcanivorax borkumensis in 1992. This bacterium is abundant in marine environments affected by oil spills, where it helps to degrade alkanes and, under such conditions, produces a glycine-glucolipid biosurfactant. The biosurfactant enhances the bacterium’s attachment to oil droplets and facilitates the uptake of hydrocarbons. Due to its useful properties expected, there is interest in the biotechnological production of this biosurfactant. To support this effort analytically, a method combining reversed-phase high-performance liquid chromatography (HPLC) with high-resolution mass spectrometry (HRMS) was developed, allowing the separation and identification of glycine-glucolipid congeners. Accurate mass, retention time, and characteristic fragmentation pattern were utilized for species assignment. In addition, charged-aerosol detection (CAD) was employed to enable absolute quantification without authentic standards. The methodology was used to investigate the glycine-glucolipid production by A. borkumensis SK2 using different carbon sources. Mass spectrometry allowed us to identify congeners with varying chain lengths (C6–C12) and degrees of unsaturation (0–1 double bonds) in the incorporated 3-hydroxy-alkanoic acids, some previously unknown. Quantification using CAD revealed that the titer was approximately twice as high when grown with hexadecane as with pyruvate (49 mg/L versus 22 mg/L). The main congener for both carbon sources was glc-40:0-gly, accounting for 64% with pyruvate and 85% with hexadecane as sole carbon source. With the here presented analytical suit, complex and varying glycolipids can be identified, characterized, and quantified, as here exemplarily shown for the interesting glycine-glucolipid of A. borkumensis.Graphical

Diamide-based screening method for the isolation of improved oxidative stress tolerance phenotypes in Bacillus mutant libraries.

The bacterium Bacillus subtilis is of high importance both as a model organism for Gram-positive bacteria and as an industrial workhorse in the production of biomolecules. In recent years, advancements have been made to engineer the bacterium even further toward industrial applications. In this study, we present a novel screening method for mutant libraries using diamide, an oxidizing agent that binds free thiols and creates disulfide bonds between them, thereby causing a so-called "disulfide stress" in bacteria. The method shows promise to selectively identify phenotypes in B. subtilis with improved tolerance toward oxidative and disulfide-associated stress. Phenotypes initially identified by transposon mutagenesis were recreated through targeted gene deletions. Among the resulting deletion mutants, the largest difference in diamide tolerance compared to the parental strain was observed for pfkA and ribT deletion strains. A proteomics analysis showed that diamide tolerance can be achieved through different routes involving increased expression of stress management proteins and reduced availability or activity of the RNA degradosome. We conclude that our screening method allows the facile identification of Bacillus strains with improved oxidative stress tolerance phenotypes. IMPORTANCE During their life cycle, bacteria are exposed to a range of different stresses that need to be managed appropriately in order to ensure their growth and viability. This applies not only to bacteria in their natural habitats but also to bacteria employed in biotechnological production processes. Oxidative stress is one of these stresses that may originate either from bacterial metabolism or external factors. In biotechnological settings, it is of critical importance that production strains are resistant to oxidative stresses. Accordingly, this also applies to the major industrial cell factory Bacillus subtilis. In the present study, we, therefore, developed a screen for B. subtilis strains with enhanced oxidative stress tolerance. The results show that our approach is feasible and time-, space-, and resource-efficient. We, therefore, anticipate that it will enhance the development of more robust industrial production strains with improved robustness under conditions of oxidative stress.

Systematic sequence engineering enhances the induction strength of the glucose-regulated GTH1 promoter of Komagataella phaffii.

The promoter of the high-affinity glucose transporter Gth1 (PGTH1) is tightly repressed on glucose and glycerol surplus, and strongly induced in glucose-limitation, thus enabling regulated methanol-free production processes in the yeast production host Komagataella phaffii. To further improve this promoter, an intertwined approach of nucleotide diversification through random and rational engineering was pursued. Random mutagenesis and fluorescence activated cell sorting of PGTH1yielded five variants with enhanced induction strength. Reverse engineering of individual point mutations found in the improved variants identified two single point mutations with synergistic action. Sequential deletions revealed the key promoter segments for induction and repression properties, respectively. Combination of the single point mutations and the amplification of key promoter segments led to a library of novel promoter variants with up to 3-fold higher activity. Unexpectedly, the effect of gaining or losing a certain transcription factor binding site (TFBS) was highly dependent on its context within the promoter. Finally, the applicability of the novel promoter variants for biotechnological production was proven for the secretion of different recombinant model proteins in fed batch cultivation, where they clearly outperformed their ancestors. In addition to advancing the toolbox for recombinant protein production and metabolic engineering of K. phaffii, we discovered single nucleotide positions and correspondingly affected TFBS that distinguish between glycerol- and glucose-mediated repression of the native promoter.

СТАБІЛЬНИЙ РОЗВИТОК БІОТЕХНОЛОГІЧНОГО ВИРОБНИЦТВА В КРИЗОВИХ УМОВАХ

The article examines the peculiarities of risks for the biotech production development in Ukraine and in the world. Biotechnological production, especially in the agricultural sector, has always been and remains the most vulnerable to military operations, social unrest, natural disasters, extraordinary events, etc. Considering the insufficient use of the biotechnological production potential of Ukraine, special attention should be paid to the development of this industry with planned provision of stable development both during the war and after its end. Global trends in sales volumes of shares of innovative biotechnological companies were analyzed. As for Ukraine, in 2021, the investment and innovation activities of agricultural producers intensified and reached a maximum result of 2.5 billion dollars. USA, which is one of the best results during the years of Ukraine's independence. in recent years, the total amount of capital investment per hectare of land was from 70 to 100 dollars. USA. Protest, according to economists, only under the conditions of capital investments from USD 150. US/ha, it can be argued that the country is developing in the direction of innovation and investment modernization. The article identifies groups of main risks for biotechnological industries in Ukraine and the world. It is possible to increase the volumes of state support for biotechnological production in the agricultural sector and the attraction of private investments, which is especially relevant in crisis conditions and global uncertainty. Stable development of biotechnological production in Ukraine is possible through digitization and automation of management and production processes, as well as taking into account all the risks inherent in this field.

Overexpression of BAPT and DBTNBT genes in Taxus baccatain vitro cultures to enhance the biotechnological production of paclitaxel.

Paclitaxel is one of the most effective anticancer drugs ever developed. Although the most sustainable approach to its production is provided by plant cell cultures, the yield is limited by bottleneck enzymes in the taxane biosynthetic pathway: baccatin-aminophenylpropanoyl-13-O-transferase (BAPT) and 3'-N-debenzoyltaxol N-benzoyltransferase (DBTNBT). With the aim of enhancing paclitaxel production by overcoming this bottleneck, we obtained distinct lines of Taxus baccata in vitro roots, each independently overexpressing either of the two flux-limiting genes, BAPT or DBTNBT, through a Rhizobium rhizogenes A4-mediated transformation. Due to the slow growth rate of the transgenic Taxus roots, they were dedifferentiated to obtain callus lines and establish cell suspensions. The transgenic cells were cultured in a two-stage system and stimulated for taxane production by a dual elicitation treatment with 1 μm coronatine plus 50 mm of randomly methylated-β-cyclodextrins. A high overexpression of BAPT (59.72-fold higher at 48 h) and DBTNBT (61.93-fold higher at 72 h) genes was observed in the transgenic cell cultures, as well as an improved taxane production. Compared to the wild type line (71.01 mg/L), the DBTNBT line produced more than four times higher amounts of paclitaxel (310 mg/L), while the content of this taxane was almost doubled in the BAPT line (135 mg/L). A transcriptional profiling of taxane biosynthetic genes revealed that GGPPS, TXS and DBAT genes were the most reactive to DBTNBT overexpression and the dual elicitation, their expression increasing gradually and constantly. The same genes exhibited a pattern of isolated peaks of expression in the elicited BAPT-overexpressing line.

Multi-functional xylanase from Aspergillus sydowii: biosynthesis of nanoconjugates, optimization by Taguchi approach and biodeinking potential

The search for effective production of xylanase which is an important industrial enzyme led to the present study that explored xylanase production by Aspergillus sydowii SF through Taguchi optimization that incorporated nanoconjugates in submerged fermentation. Calcium and zinc oxide nanoconjugates biosynthesized by xylanase were characterized via UV-Vis spectroscopy, Fourier transform infrared spectroscopy, and Transmission electron microscopy (TEM). The xylanase-mediated calcium oxide and zinc oxide nanoconjugates with λmax of 374 and 316 nm, respectively, and were 5.32–17.69 nm in size. Xylanase production was improved by 2.90–10.58 folds (64.24–234.15 U/mL) through Taguchi optimization cum nanoconjugates, and ANOVA showed that nanoconjugates contributed 13.62–65.97% to improved production. The xylanase had up to 88.38% deinking activity, with 49.60–84.64% removal of blue color. The remarkable xylanase production, its use to biosynthesize nanoconjugates and biodeinking potentials contribute to the development of versatile biocatalysts with applications in biotechnology, nanotechnology, and sustainable paper production. To the best of our knowledge, this represents the first report of xylanase for biosynthesis of calcium oxide and zinc oxide nanoparticles, as well as nanosupplementation to induce xylanase production, which can open new vista in bioprocess optimization.

Fungi from the body surface of Spodoptera frugiperda (Lepidoptera: Noctuidae) and bioassay of insecticidal activity

Spodoptera frugiperda (Lepidoptera: Noctuidae) is an important insect pest in Brazil and worldwide, and its control is based mainly on chemical methods that are harmful to the environment and human and animal health. We investigated the fungal community associated with the body surface of S. frugiperda and evaluated the potential of members of this fungal community to act as biocontrol agents. The caterpillars were collected in the field, reared in the laboratory on a natural diet, evaluated for association with fungi on their surface and the environment, and subjected to a bioassay for insecticidal activity. Our results suggest that fungi are often associated with the body of S. frugiperda, as it was possible to obtain these microorganisms from all insects sampled, with a higher frequency of filamentous fungi than yeast. Fusarium verticillioides was the most frequent filamentous fungus species (F3 = 42.1%), followed by Aspergillus aureolus (F2 = 36.8%). Candida pseudointermedia was the most frequent yeast species (L1 = 57.1%). Aspergillus aureolus F2 was the only strain that exhibited toxicity against S. frugiperda and can be considered a good candidate to be explored from the perspective of obtaining biotechnological products of interest for agriculture.

Parameters, practices, and preferences for regulatory review of emerging biotechnology products in food and agriculture.

This paper evaluates the U.S. regulatory review of three emerging biotechnology products according to parameters, practices, and endpoints of assessments that are important to stakeholders and publics. First, we present a summary of the literature on variables that are important to non-expert publics in governing biotech products, including ethical, social, policy process, and risk and benefit parameters. Second, we draw from our USDA-funded project results that surveyed stakeholders with subject matter expertise about their attitudes towards important risk, benefit, sustainability, and societal impact parameters for assessing novel agrifood technologies, including biotech. Third, we evaluate the regulatory assessments of three food and agricultural biotechnology case studies that have been reviewed under U.S. regulatory agencies and laws of the Coordinated Framework for the Regulation of Biotechnology, including gene-edited soybeans, beef cattle, and mustard greens. Evaluation of the regulatory review process was based on parameters identified in steps 1 and 2 which were deemed important to both publics and stakeholders. Based on this review, we then propose several policy options for U.S. federal agencies to strengthen their oversight processes to better align with a broader range of parameters to support sustainable agrifood products that rely on novel technologies. These policy options include 1) those that would not require new institutions or legal foundations (such as conducting Environmental Impact Statements and/or requiring a minimal level of safety data), 2) those that would require a novel institutional or cross-institutional framework (such as developing a publicly-available website and/or performing holistic sustainability assessments), and 3) those that would require the agencies to have additional legal authorities (such as requiring agencies to review biotech products according to a minimal set of health, environmental, and socio-economic parameters). Overall, the results of this analysis will be important for guiding policy practice and formulation in the regulatory assessment of emerging biotechnology products that challenge existing legal and institutional frameworks.

Raman spectroscopy with near IR excitation for study of structural components of cyanobacterial phycobilisomes

Cyanobacteria are prokaryotes that carry out oxygenic photosynthesis and are widely used as a model in scientific research. Being a rich source of biologically active compounds, they are also currently considered as a promising object for use in biotechnologies. For solving research or applied problems of cyanobacteria study, detection, identifying and monitoring of biotechnological production different kinds of laser spectroscopy can be a promising tools. In the present work Raman spectroscopy with IR excitation (IR Raman) is used to analyze phycobiliproteins, structural components of phycobilisomes – light-harvesting antenna – of the cyanobacterium Synechocystis sp. PCC6803. Excitation wavelengths in red/near infrared range were chosen to focus on the vibrational spectra and avoid an influence of pigments fluorescence.− The Raman spectra with excitation in near infrared and UV–visible absorption spectra were measured from wild type (WT) of Synechocystis sp. PCC6803, the mutant lacking C-phycocyanin (CK), and the mutant totally devoid of phycobilisomes (PAL). Spectral information is analyzed in comparison with data on structural and functional state of photosynthetic system of the cyanobacteria. It has been shown that IR Raman spectroscopy makes it possible to analyze in detail the structural disorders in phycobilisomes and to discuss the carotenoids-based mechanisms of compensation for this deficiency.

Isolation and characterization of bacterial cellulose produced from soybean whey and soybean hydrolyzate

Soybean whey and soybean hydrolyzate can be used for the biotechnological production of high-value products. Herein, we isolate soybean whey (SW)-and soybean hydrolyzate (SH)-derived bacterial cellulose (BC, produced by kombucha) and characterize it by a range of instrumental techniques to reveal differences in micromorphology, crystallinity, and themal behavior. Studies have shown that the amounts of wet state BC produced from HS, SW and SH was 181 g/L, 47 g/L and 83 g/L, respectively. The instrumental analysis of BC, included SEM, AFM, FT-IR, XRD and TGA. It is shown that the FT-IR spectra of BC have a similar character, but we found differences in the micromorphology,crystallinity and thermal temperature of BC. The minimum average widths of the fibers produced from SH medium was 100 ± 29 nm. The CrI values of BC produced from SH medium was 61.8%. The maximum thermal degradation rate temperature of BC produced from SW medium was 355.73 °C. The combined results demonstrate that soybean industrial waste can be used as a cost-effective raw material for BC production.

High-cell-density cultivation of Vibrio natriegens in a low-chloride chemically defined medium

Vibrio natriegens is a halophilic bacterium with the fastest generation time of non-pathogenic bacteria reported so far. It therefore has high potential as a production strain for biotechnological production processes or other applications in biotechnology. Culture media for V. natriegens typically contain high sodium chloride concentrations. The corresponding high chloride concentrations can lead to corrosion processes on metal surfaces in bioreactors. Here we report the development of a low-chloride chemically defined medium for V. natriegens. Sodium chloride was completely replaced by the sodium salts disodium hydrogen phosphate, disodium sulfate, and sodium citrate, while keeping the total concentration of sodium ions constant. The use of citrate prevents the occurrence of precipitates, especially of ammonium magnesium phosphate. With this defined medium, high-cell-density fed-batch cultivations in laboratory-scale bioreactors using exponential feeding yielded biomass concentrations of more than 60 g L−1.Key pointsA defined medium for V. natriegens that only contains traces of chloride was developedCorrosion processes on metal surfaces in industrial bioreactors can thus be preventedHigh yields of biomass can be achieved in fed-batch cultivation with this medium

Production of (hydroxy)benzoate-derived polyketides by engineered Pseudomonas with in situ extraction

Polyketides from (hydroxy)benzoates are an interesting group of plant polyphenolic compounds, whose biotechnological production is so far underrepresented due to their challenging heterologous biosynthesis. Efficient heterologous production of 2,4,6-tri- and 2,3′,4,6-tetrahydroxybenzophenone, 3,5-dihydroxybiphenyl, and 4-hydroxycoumarin by whole-cell biocatalysis in combination with in situ product extraction with an organic solvent was demonstrated. Production was highly dependent on the used CoA ligase and polyketide synthase type III. Therefore, different combinations of polyketide synthases and benzoate-CoA ligases were evaluated for their biosynthesis performance in the solvent-tolerant Pseudomonas taiwanensis VLB120. A solvent screening yielded 2-undecanone as biocompatible, extraction-efficient solvent with good phase separation. In aqueous-organic two-phase cultivations, this solvent extraction circumvents product instability in the aqueous cultivation medium, and it increases yields by reducing inhibitory effects. Complete de novo synthesis from glucose of all (hydroxy)benzoate-derived polyketides was achieved in two-phase cultivations with metabolically engineered strains. Additionally, mutasynthesis was applied to obtain fluorinated benzophenone derivatives.