Pilot-scale Production Research Articles

Catalytic Thermal Cracking of Postconsumer Waste Plastics to Fuels. 2. Pilot-Scale Thermochemical Conversion

Synthetic gasoline and diesel fuels were prepared via catalytic and noncatalytic pyrolysis of waste polyethylene and polypropylene plastics followed by distillation of plastic crude oils. Reaction conditions optimized using a 2 L batch reactor were applied to pilot-scale production of plastic crude oil from polypropylene. The optimum conditions on the pilot-scale system were a reaction temperature of 500 °C and a residence time of 4.7 min. Plastic crude oil yields at pilot scale were comparable to those of the batch scale (70–80%). Plastic crude oils obtained from pyrolysis were distilled into the boiling point range of motor gasoline, diesel no. 1, gas oil, and vacuum gas oil range fractions. The elemental composition of the crude oil and its distillates were similar to the starting plastic material. Fuel properties were studied for both neat and in blends (5% and 20%) with ultralow sulfur diesel fuel (ULSD). Excellent low temperature properties were obtained for some of the samples, as indicated by a po...

Optimization of flocculation with tannin-based flocculant in the water reuse and lipidic production for the cultivation of Acutodesmus obliquus

ABSTRACTThis paper evaluated the optimization of natural flocculant in different conditions in a tubular photobioreactor using swine wastewater effluent as culture media in a pilot-scale microalgae production plant. This study aimed to assess the flocculation efficiency of Tanfloc SG via a central composite design (CCD), with varying Tanfloc SG concentration, biomass concentration and pH. Subsequently, the microalga Acutodesmus obliquus was cultivated in medium obtained from the recycled recovery of microalgae cells via flocculation with Tanfloc SG. Results showed that the recycled medium after flocculation with Tanfloc SG had a positive effect on the biomass and lipid production of A. obliquus.

Precursor suitability and pilot scale production of super activated carbon for greenhouse gas adsorption and fuel gas storage

Raw and calcined petroleum cokes of Indian origin were characterized and screened as a carbon precursor for the preparation of activated carbon on medium and pilot scale by chemical activation method. Raw petroleum coke (RPC) was found more suitable precursor for preparation of activated carbon, whereas the enhanced graphitic arrangement limits the applicability of calcined petroleum coke. The suitability of petroleum coke as activated carbon precursor was correlated with its physical properties. Super activated carbon (SAC) obtained from RPC exhibited very high specific surface area (3578m2g−1) with ultra-microporosity ranges from 0.4 to 0.7nm. The equilibrium adsorption of CO2, CH4, CO, and N2 measured on powder SAC at different temperatures evidenced its applicability for gas separation through high adsorption capacity and selectivity. SAC also showed the high fuel gas storage capacity, H2 (26.67mmolg−1 at 77K and 3000kPa) and CH4 (10.87mmolg−1 at 303K and 3700kPa) due to its high specific surface area and microporous textural property. The production of SAC was also demonstrated for pilot scale and examined for CH4 storage. The transformation of powder SAC into pellets using bentonite clay as a binder to provide better mechanical strength with enhanced CH4 adsorption (on a volume basis) made it viable for practical application.

Pilot scale production, kinetic modeling, and purification of glycine betaine and trehalose produced from Actinopolyspora halophila (MTCC 263) using acid whey: A dairy industry effluent

Dairy factories manufacturing Greek yoghurt generate huge quantities of acid whey, an effluent which has serious ecological ramifications. In this work, we have used Actinopolyspora halophila (MTCC 263), an extreme halophile that utilized acid whey for pilot scale production of glycine betaine and trehalose which are commercially important compounds having innumerable applications in many industries. Batch bioreactor process with 200rpm agitation and 3vvm aeration gave a maximum production of 13.57±0.39gL−1 glycine betaine and 5.09±0.19gL−1 of trehalose. Kinetic models were also evaluated for production (biomass, glycine betaine and trehalose) and substrate utilization (lactose, glycine and total nitrogen) in A. halophila. Screening of resins for chromatographic separation of glycine betaine and trehalose showed strong cation exchange resin to be the most effective. The recovery of glycine betaine was 86.04±2.86% with purity of 82.26% and that of trehalose was 90.04±1.17% with purity of 94.47%. The findings of this work could benefit the dairy industries to plan on utilization of acid whey and generate revenue while simultaneously preventing environmental and economic repercussions caused by it.

A facile semi-synthetic approach towards halogen-substituted aminobenzoic acid analogues of platensimycin

Platensimycin (PTM), produced by several strains of Streptomyces platensis, is a promising drug lead for infectious diseases and diabetes. The recent pilot-scale production of PTM from S. platensis SB12026 has set the stage for the facile semi-synthesis of a focused library of PTM analogues. In this study, gram-quantity of platensic acid (PTMA) was prepared by the sulfuric acid-catalyzed ethanolysis of PTM, followed by a mild hydrolysis in aqueous lithium hydroxide. Three PTMA esters were also obtained in near quantitative yields in a single step, suggesting a facile route to make PTMA aliphatic esters. 1-[Bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium 3-oxid hexafluorophosphate (HATU)-catalyzed coupling of PTMA and 33 aminobenzoates resulted in the synthesis of 28 substituted aminobenzoate analogues of PTM, among which 26 of them were reported for the first time. Several of the PTM analogues showed weak antibacterial activity against methicillin-resistant Staphylococcus aureus. Our study supported the potential utility to integrate natural product biosynthetic and semi-synthetic approaches for structure diversification.

Optimization and scaling-up of ITZ-based dry powders for inhalation

Dry powders for inhalation with amorphous itraconazole (ITZ) dispersed in a hydrophilic matrix were previously obtained by the spray-drying technique. This gave interesting aerodynamic and dissolution characteristics leading to promising lung pharmacokinetic and prophylaxis efficacy in a preclinical model of invasive pulmonary aspergillosis. The spray-drying allows dry powder to be obtained in a one-step process; nonetheless, the scale-up still presents a challenge in maintaining the main particle characteristics. This study aimed to investigate the feasibility of obtaining similar powder characteristics from concentrated solutions using laboratory-scale and pilot-scale spray dryer equipment. ITZ was solubilized in a solvent mixture (ethanol/ethyl acetate/water mixture 40:40:20 v/v/v) in mannitol solutions or suspensions. These mixtures were spray dried at laboratory scale to produce a solid dispersion for inhalation (SDI) containing amorphous ITZ dispersed in a mannitol matrix. A solution of 35% (So1) w/w ITZ was chosen to evaluate the scale-up process. This formulation was chosen for its high yield (60%), its amorphous ITZ content (100%), its good aerodynamic behavior (fine particle fraction - FPF = 33± 2%) and its increased dissolution profile compared to bulk ITZ. The scale-up process showed pilot-scale dry powders with a higher yield than lab-scale dry powders and similar aerodynamic performance and equivalent dissolution profiles. Moreover, all SDIs displayed improved release kinetics in comparison with bulk ITZ. Despite the slight differences between lab- and pilot-scale SDIs, this study shows that the scaling-up process allowed interesting ITZ-based SDIs to be obtained, in order to achieve pilot-scale production.

Pilot-Scale Production of Megakaryocytes/Platelets from Cord Blood CD34+ Cells in a Bottle Turning Device Culture System

Due to a donor-platelet shortage, ex vivo generated megakaryocytes/platelets have emerged as an effective substitute to alleviate thrombocytopenia. We have previously reported a "two-stage culture system" for producing megakaryocytes/platelets from CD34+ cellsand demonstrated their safety and efficacy in myeloablative murine and non-human primate models. Here, we present pilot-scale production of megakaryocytes/platelets in a bottle turning device culture system that significantly increases the yield of functional megakaryocytes/platelets.Enrichedcord blood CD34+ cells were first cultured in modified IMDM basal medium (serum-free) with the addition of stem cell factor (SCF), Flt-3 ligand (FL), thrombopoietin (TPO), and interleukin (IL)-3 in a T-25 flask. After 6 days of expansion, cells were transferred into a 2 L culture bottle with 600 ml medium in a bottle turning device at the density of 1.5×105/mL for additional 7 days. The culture medium was modified IMDM supplemented with SCF, TPO, IL-3, IL-6, and granulocyte-macrophage colony-stimulating factor (GM-CSF). At various time points, cell numbers were counted with a hemocytometer and expression of CD34, CD41a, and CD42b surface markers was monitored by flow cytometry. Resulting megakaryocytes were further confirmed by morphological examination and DNA ploidy analysis. Expression of relevant oncogenes was measured by quantitative real-time polymerase chain reaction (qPCR) for evaluating potential tumorigenicity. Moreover, these megakaryocytes were transplanted into sub-lethally irradiated NOD/SCID mice (1×106 CD41a+/CD42b+ megakaryocytes per mouse) to assess human platelet-releasing potential and function in vivo.The initial cell number was 1×106 with CD34 purity of 93.4% ±2.8%. For 6-day culture, the absolute number of total cells and CD34+ cells reached 9.3×107±1.8×107 and 4.0×107±5.6×106, respectively, which were calculated into a 92.9±18.1 and 42.8±5.2-fold increase, respectively. For additional 7-day culture in the turning bottles, 2.2×1010±3.2×109 cells were obtained with the proportions of CD41a+ and CD42b+ cells at 80.1%±7.4% and 63.6%±5.9%, respectively. Approximately 2.0×104 megakaryocytes/platelets were generated from each input CD34+ cell. These megakaryocytes were morphologically discernible as they were much larger than starting CD34+ cells with apparent lobular nuclei and numerous α-granules. DNA content analysis revealed that about 25.4%±1.3% of megakaryocytes exhibited a polyploidy level of >8N. Moreover, about 10% megakaryocytes have formed pro-platelet fragments and released platelets in cultures. Compared to initial CD34+ cells, generated megakaryocytes showed similar levels of expression of proto-oncogenes including c-Myb, N-Ras, and K-Ras whereas c-Myc, bmi-1, cyclin B, and hTERT expression was decreased, strongly suggesting that ex vivogenerated megakaryocytes are unlikely tumorigenic. Releasing of human platelets by injected megakaryocytes were detected in mouse peripheral blood with a percentage of 0.5%±0.1% as early as 30 min following transplantation, after which the percentage of human platelets increased rapidly with a peak level of 3.2%±0.6% at about 4-6 h post-transplantation. The half-life of released platelets in mice was about 10 h and about 23±6 human platelets were released per megakaryocyte in the transplanted mice. Furthermore, these platelets were activated, expressing CD62P after stimulation by ADP, suggesting that released human platelets in mice are functional.Combined, we have established a bottle turning device culture system for pilot-scale production of megakaryocytes/platelets ex vivo. One unit of cord blood (80 ml) with 2×106 CD34+ cells can generate 4×1010 megakaryocytes/platelets that are sufficient for treating 130 patients (with an average weight of 60 kg and infusion cell number 5×106cells/kg). In conclusion, our new culture system is capable of manufacturing GMP-grade megakaryocytes/platelets sufficient for various clinical applications. DisclosuresRen:Biopharmagen Corp: Employment. Jiang:Biopharmagen Corp: Consultancy.

Pilot-scale production of Omija-cheong by low temperature incubation: An assessment of quality characteristics

Omija-cheong, concentrated extracts from sugar-treated Omija fruit (Schisandra chinensis Baillon), is produced by traditional manner in Korea. The quality characteristics of Omija-cheong processed at low temperature with a pilot-scale were investigated to optimize the incubation time. With increasing incubation time in processing Omija-cheong, the pH level of Omija-cheong remained constant, while titratable acidity and organic acids increased. Fresh Omija fruits contained citric, malic and succinic acids, most of which were extracted into concentrated extracts after 37 days of incubation and reached to the stable concentration after 47 days of incubation. Titratable acidity in Omija-cheong gradually increased from 1.18% to 2.71%, and also was correlated with total concentration of organic acids. About 80% of supplemented sucrose for manufacturing Omija-cheong was converted into glucose and fructose until 68 days of incubation, and the composition of free sugars was maintained to be stable up to 138 days of incubation. The contents of total flavonoids and phenolic compounds in Omija-cheong were 24.1 mg-GAE/L and 1,635 mg-QE/L at 57 days of incubation, which were more than 9 and 5 times higher than those in Omija fruits, respectively. From the quality characteristics in processing Omija-cheong by low-temperature incubation, more than 60 days of incubation is required for the constant quality and value-added beverage.

Pilot-Scale Production and Thermostability Improvement of the M23 Protease Pseudoalterin from the Deep Sea Bacterium Pseudoalteromonas sp. CF6-2.

Pseudoalterin is the most abundant protease secreted by the marine sedimental bacterium Pseudoalteromonas sp. CF6-2 and is a novel cold-adapted metalloprotease of the M23 family. Proteases of the M23 family have high activity towards peptidoglycan and elastin, suggesting their promising biomedical and biotechnological potentials. To lower the fermentive cost and improve the pseudoalterin production of CF6-2, we optimized the fermentation medium by using single factor experiments, added 0.5% sucrose as a carbon source, and lowered the usage of artery powder from 1.2% to 0.6%. In the optimized medium, pseudoalterin production reached 161.15 ± 3.08 U/mL, 61% greater than that before optimization. We further conducted a small-scale fermentation experiment in a 5-L fermenter and a pilot-scale fermentation experiment in a 50-L fermenter. Pseudoalterin production during pilot-scale fermentation reached 103.48 ± 8.64 U/mL, 77% greater than that before the medium was optimized. In addition, through single factor experiments and orthogonal tests, we developed a compound stabilizer for pseudoalterin, using medically safe sugars and polyols. This stabilizer showed a significant protective effect for pseudoalterin against enzymatic thermal denaturation. These results lay a solid foundation for the industrial production of pseudoalterin and the development of its biomedical and biotechnological potentials.

The Key Technology for the Pilot-Scale Production of Chinese Commercial <em>Za</em> Wine

The study aimed to explore the key technology for the pilot-scale production of Commercial <em>Za</em> Wine (CZW), including processing methods of the raw materials, screening fermentation starters and yeast and other brewing technics about CZW. As an ancient low-alcohol drink, <em>Za</em> wine is very popular in the Qiang ethnic minority areas of China. In order to expand the production of Traditional <em>Za</em> Wine (TZW) to meet the increasing demands of consumers and tourists, it is necessary to industrialize the production of <em>Qiang Za</em> wine. Hence the key techniques for the pilot-scale production of CZW were explored and the results are as follows: hull-less barley (the main raw material) was soaked in water at 60°C for 12 h then crushed to plum petal shapes for saccharification. The <em>koji</em> should be rice <em>koji</em> made from <em>A. flavus</em> QJ and <em>Rhizopus</em> Q303. The LI8 and YW yeasts were the best choice for brewing the wine. For the production of CZW with special requirements on flavour ingredients, an appropriate amount of aroma yeast LII 1-1 could be added. In addition, for producing the semi-sweet CZW, the concentrated saccharification liquid mix from hull-less barley and glutinous rice can be used during the postfermentation period. CZW from the pilot test was yellow and transparent, possessed the typical characteristics of TZW, had higher alcohol content, liquor yield, better wine appearance and circulation than those of TZW. Meanwhile, CZW had reached the Grade one standard for semi-sweet fermented wine of the Chinese Yellow Wine National Standard. This study initiates the research for the key producing technology of CZW.

Standardization of the manufacturing procedure for Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine

Ethnopharmacological relevancePinelliae Rhizoma (PR), the dried tuber of Pinellia ternata (Thunb.) Breit., is a traditional Chinese medicinal herb. It is commonly used for treating cancer, cough and phlegm. To treat cancer, Chinese medicine practitioners often use raw PR; while to treat cough and phlegm, they usually use Pinelliae Rhizoma Praeparatum cum Zingibere et Alumine (PRZA, raw PR processed with ginger juice and alumen as adjuvant materials). Currently, the producing protocol of PRZA varies greatly among different places in China. This study aims to standardize the manufacturing procedure for PRZA. We also evaluated the impact of processing on the bioactivities and chemical profile of raw PR. Materials and methodsWe used the orthogonal design to optimize the manufacturing procedure of PRZA at bench scale, and validated the optimized procedure in pilot-scale production. The MTT assay was used to compare the cytotoxicities of raw PR and PRZA in hepatocellular carcinoma HepG2 cells. Animal models (ammonia liquor-induced cough model and phenol red secretion model) were used to compare the antitussive and expectorant effects of raw PR and PRZA, respectively. The chemical profiles of raw PR and PRZA samples were compared using a newly developed ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry (UPLC/Q-TOF-MS) method. ResultsThe standardized manufacturing procedure for PRZA is as follows: soak raw PR in water until the center of the cut surface is devoid of a dry core, after that, boil the herb in water (for each 100kg raw PR, 12.5kg alumen and 25L freshly squeezed ginger juice are added) for 6h, and then take out and dry them. The cytotoxicity of PRZA was less potent than that of raw PR. Intragastric administration of raw PR or PRZA demonstrated antitussive and expectorant effects in mice. These effects of PRZA were more potent than that of raw PR at the dose of 3g/kg. By comparing the chemical profiles, we found that six peaks were lower, while nine other peaks were higher in PRZA than in raw PR. Six compounds corresponding to six individual changed peaks were tentatively identified by matching with empirical molecular formulae and mass fragments. ConclusionThe manufacturing procedure for PRZA was standardized. This protocol can be used for PRZA industrial production. The bioactivity assay results of raw PR and PRZA (produced using the standardized protocol) support the common practice for the clinical applications of these two decoction pieces. Moreover, raw PR and PRZA showed different chemical profiles. Further studies are warranted to establish the relationship between the alteration of chemical profiles and the changes of medicinal properties caused by processing.

Conversion of Solid Waste to Diesel via Catalytic Pressureless Depolymerization: Pilot Scale Production and Detailed Compositional Characterization

Solid waste is considered as one of the key feedstocks for the chemical industry to stimulate the world’s transition toward a circular economy. Therefore, a novel production process, catalytic pressureless depolymerization (CPD), for conversion of waste to high-energy density liquid fuel has been studied. More specifically, the organic fractions recovered from demolition waste and municipal solid waste were liquefied and deoxygenated in a CPD pilot plant with 150 L h–1 (4.2 × 10–5 m3 s–1) liquid fuel capacity. The produced fuels were characterized by elemental analysis, comprehensive two-dimensional gas chromatography (GC × GC), and the ISO tests for automotive diesel established by the EN 590:2009 Standard. The studied fuels showed very low oxygen contents ( 40 wt %). The carbon range of the fuel obtained from demolition wood was wider than that of the fuel obtained from municipal solid waste (C5–C29 vs. C6–C22). The flash points (54, 46 °C), the sulfur contents ...

Role of Graphene Oxide Liquid Crystals in Hydrothermal Reduction and Supercapacitor Performance.

The formation of liquid crystal (LC) phases in graphene oxide (GO) aqueous solution is utilized to develop high-performance supercapacitors. To investigate the effect of LC formation on the properties of subsequently reduced GO (rGO), we compare films prepared through blade-coating of viscous LC-GO solution and ultrasonic spray-coating of diluted GO aqueous dispersion. After hydrothermal reduction under identical conditions, the films show different morphology, oxygen content, and specific capacitance. Trapped water in the LC GO film plays a role in preventing restacking of sheets and facilitating the removal of oxygenated groups during the reduction process. In device architectures with either liquid or polymer electrolyte, the specific capacitance of the blade-coated film is twice as high as that of the spray-coated one. For a blade-coated film with mass loading of 0.115 mg/cm(2), the specific capacitance reaches 286 F/g in aqueous electrolyte and 263 F/g in gelled electrolyte, respectively. This study suggests a route to pilot-scale production of high-performance graphene supercapacitors through blade-coated LC-GO films.

Production methods for reliable construction of ultra-high-performance concrete (UHPC) structures

Mix design procedures were developed around the core strategy of maximizing the packing and ensuring distributed size distribution of the particulate matter in UHPC for achieving ultra-high strength levels and desired fresh mix workability using locally available materials and concrete-making facilities. The linear density packing model and the continuously graded particle packing model provided the theoretical basis for proportioning the UHPC mixtures. Criteria were devised for selection of local materials to be used in UHPC structures. Experimental investigations were conducted in order to refine and optimize the UHPC mix proportions, yielding the targeted compressive strength of 200 MPa (30 ksi). The final UHPC mix design developed in the study was used for pilot-scale production of a large 1 m × 1 m × 1 m (3.3 ft × 3.3 ft × 3.3 ft) reinforced concrete block, with UHPC batched in a ready-mixed concrete plant and mixed/transported using a conventional concrete truck (transit mixer).

Pilot-scale aqueous two-phase floatation for direct recovery of lipase derived from Burkholderia cepacia strain ST8

Abstract The efficient and economical pilot-scale production of lipase is necessary for meeting the growing demand of lipase especially in bioprocessing industry. Aqueous two-phase flotation (ATPF) is a purification technique that can be applied in the recovery and purification of biomolecules. ATPF is based on a combination of aqueous two-phase systems (ATPS) and solvent sublation (SS). In this report lipase was recovered and purified from the fermentation broth of Burkholderia cepacia (B. cepacia) using an alcohol/salt ATPF system on a pilot scale. The working parameters of ATPF, including concentration of crude lipase feedstock, types of alcohol and salt, concentrations of alcohol and salt, volumes of buffer solution and alcohol, were investigated for their effects on the partitioning behavior of lipase in ATPF. ATPF comprised of 1-propanol and ammonium sulphate was successfully established for feasible and cost effective separation of B. cepacia ST8 lipase from liquid fermentation broth. The alcohol/salt ATPF system showed a purification factor of 12.2, a separation efficiency of 93% and a selectivity of 40. Furthermore, a comparison has been made between small-scale and large-scale ATPF production. Our results showed that this novel pilot-scale ATPF has the potential to be applied at industrial scale.

Rheological behavior of highly loaded cellulose nanocrystal/poly(vinyl alcohol) composite suspensions

Recent emphasis on the pilot scale production of cellulosic nanomaterials has increased interest in the effective use of these materials as reinforcements for polymer composites. An important, enabling step to realizing the potential of cellulosic nanomaterials in their applications is the materials processing of CNC/polymer composites through multiple routes, i.e. melt, solution, and aqueous processing methods. Therefore, the objective of this research is to characterize the viscoelastic behavior of aqueous nanocomposite suspensions containing cellulose nanocrystals (CNCs) and a water-soluble polymer, poly(vinyl alcohol) (PVA). Specifically, small amplitude oscillatory shear measurements were performed on neat PVA solutions and CNC-loaded PVA suspensions. The experimental results indicated that the methods used in this study were able to produce high-quality nanocomposite suspensions at high CNC loadings, up to 67 wt% with respect to PVA. Additionally, the structure achieved in the nanocomposite suspensions was understood through component attributes and interactions. At CNC loadings near and less than the percolation threshold, a polymer mediated CNC network was present. At loadings well above the percolation threshold, a CNC network was present, indicated by limited molecular weight dependence of the storage modulus. Overall, these results provide increased fundamental understanding of CNC/PVA suspensions that can be leveraged to develop advanced aqueous processing methods for these materials.

Pilot scale production and in vitro gastro-small intestinal digestion of self-assembled recrystallised starch (SARS) structures

Two commercial maize starches (Hylon VII, HA7; and normal maize starch, MS) and a potato starch were processed in the presence of palmitic acid (C16:0, Palm) at 140 °C followed by retrogradation in order to produce self-assembled recrystallised starches (SARS). The new starch structures prepared from HA7 exhibited a stronger birefringence pattern under polarised light and greater relative crystallinity (%) than those prepared from potato and normal MS. Also, the SARS from HA7 showed a typical Vh pattern (2Ө: 8.5°, 15°, 23°) confirming a strong inclusion complexation between amylose and fatty acid. Effect of other fatty acids (stearic, C18:0 and oleic, C18:1) on SARS formation was also studied using HA7. The degree of relative crystallinity (%) of these samples showed an order of palmitic > oleic > stearic, with the former also showing greater yield (YSARS). The transition temperatures and enthalpies of melting or dissolution for SARS prepared from HA7 and three fatty acids (further referred to as HA7-SARS) ranged between 101 and 131 °C and 11–18jg−1, respectively. The scanning electron micrographs of the freeze-dried HA7-SARS showed the presence of aggregated round and disc/torus shaped morphologies in varying amounts. An in vitro starch digestion model was used to study the kinetics of glucose release during digestion of ground and cooked HA7-SARS for 120 min. All the HA7-SARS samples exhibited slower and significantly lower overall starch hydrolysis than the native HA7 starch (70%), with the SARS prepared using palmitic acid showing the lowest hydrolysis (44%). Digesta from the latter also showed the presence of intact microparticles resistant to gastro-small intestinal digestion.

Improvement of Ayran quality by the selection of autochthonous microbial cultures

Ayran is a traditional Turkish milk drink which is fermented and salted. Inadequate production and storage conditions contribute to its variable organoleptic quality and stability during shelf-life. A thorough physico-chemical, nutritional and microbial characterization of artisanal Ayran was carried out in order to standardize its overall quality without altering its original traits. Ayran microbial ecosystem was largely dominated by Streptococcus thermophilus (ST) and Lactobacillus delbrueckii subsp. bulgaricus (LDB). High counts of other lactic acid bacteria species, including Lactobacillus helveticus (LH), Lactobacillus fermentum (LF), and Lactobacillus paracasei (LP), were also found. Selected LDB, LP and LH strains grew well in milk displaying fast acidification and high proteolysis, differently from ST and LF strains that did not cause noticeable changes. A selected autochthonous three-strain culture (TSC), composed of one strain of LDB, LP and ST, was applied for the pilot-scale production of traditional Ayran. The Ayran produced with this TSC resulted in the most extensive shelf-life (one month) and in the best terms of its nutritional and sensory quality nevertheless altering its typical pleasant yogurt and cottage cheese notes. This TSC is at disposal of SMEs who need to standardize the overall quality of this traditional fermented milk, preserving its typical traits.

Titer improvement and pilot-scale production of platensimycin from Streptomyces platensis SB12026.

Platensimycin (PTM) and platencin (PTN), isolated from several strains of Streptomyces platensis are potent antibiotics against multi-drug resistant bacteria. PTM was also shown to have antidiabetic and antisteatotic activities in mouse models. Through a novel genome-mining method, we have recently identified six PTM and PTN dual-producing strains, and generated several mutants with improved production of PTM or PTN by inactivating the pathway-specific transcriptional repressor gene ptmR1. Among them, S. platensis SB12026 gave the highest titer of 310mg/L for PTM. In this study, we now report titer improvement by medium and fermentation optimization and pilot-scale production and isolation of PTM from SB12026. The fermentation medium optimization was achieved by manipulating the carbon and nitrogen sources, as well as the inorganic salts. The highest titer of 1560mg/L PTM was obtained in 15-L fermentors, using a formulated medium mainly containing soluble starch, soybean flour, morpholinepropanesulfonic acid sodium salt and CaCO3. In addition, a polyamide chromatographic step was applied to facilitate the purification and 45.14g of PTM was successfully obtained from a 60L scale fermentation. These results would speed up the future development of PTM as human medicine.

Improved operational stability of d-psicose 3-epimerase by a novel protein engineering strategy, and d-psicose production from fruit and vegetable residues

The aim of the present work was to improve stability of d-psicose 3-epimerase and biotransformation of fruit and vegetable residues for d-psicose production. The study established that N-terminal fusion of a yeast homolog of SUMO protein – Smt3 – can confer elevated optimal temperature and improved operational stability to d-psicose 3-epimerase. The Smt3-d-psicose 3-epimerase conjugate system exhibited relatively better catalytic efficiency, and improved productivity in terms of space–time yields of about 8.5kgL−1day−1. It could serve as a promising catalytic tool for the pilot scale production of the functional sugar, d-psicose. Furthermore, a novel approach for economical production of d-psicose was developed by enzymatic and microbial bioprocessing of fruit and vegetable residues, aimed at epimerization of in situd-fructose to d-psicose. The bioprocessing led to achievement of d-psicose production to the extent of 25–35% conversion (w/w) of d-fructose contained in the sample.