Search

Keratinases, a subclass of proteases, are used to degrade keratin thereby forming peptones and free amino acids. Bacillus paralicheniformis strain T7 was isolated from soil and exhibited high keratinase, protease, collagenase, amylase, xylanase, lipase, and phosphatase activities. Keratinases of the strain showed maximum activity at 70°C and pH 9.0 as well as high thermal stability. A mass-spectrometric analysis identified seven peptidases with molecular masses of 26.8–154.8 kDa in the secretory proteome. These peptidases are members of S8 and S41 serine peptidase families and of M14, M42, and M55 metallopeptidase families. Additionally, α-amylase (55.2 kDa), alkaline phosphatase (59.8 kDa), and esterase (26.8 kDa) were detected. The strong keratinolytic properties of the strain were confirmed by degradation of chicken and goose feathers, which got completely hydrolyzed within 4 days. Submerged fermentation by strain B. paralicheniformis T7 was carried out in a pilot bioreactor, where the highest keratinase production was noted after 19 h of cultivation. After the fermentation, in the culture fluid, the keratinase activity toward keratin azure was 63.6 ± 5.8 U/mL. The protease activity against azocasein was 715.7 ± 40.2 U/mL. The possibility of obtaining enzyme preparations in liquid and powder form was demonstrated, and their comparative characteristics are given. In the concentrate, the keratinase, protease, α-amylase, phosphatase, and esterase/lipase activities were 2,656.7 ± 170.4, 29,886.7 ± 642.9, 176.1 ± 16.3, 23.9 ± 1.8, and 510.9 ± 12.2 U/mL, respectively. In the lyophilizate, these activities were 57,733.3 ± 8,911.4, 567,066.7 ± 4,822.2, 2,823.0 ± 266.8, 364.2 ± 74.8, and 17,618.0 ± 610.3 U/g, respectively. In the preparation obtained by air flow drying at 55°C, these activities were 53,466.7 ± 757.2, 585,333.3 ± 4,277.1, 2,395.8 ± 893.7, 416.7 ± 52.4, and 15,328.1 ± 528.6 U/g, respectively. The results show high potential of B. paralicheniformis strain T7 as a producer of keratinases and other enzymes for applications in agricultural raw materials and technologies for processing of keratin-containing animal waste. [ABSTRACT FROM AUTHOR]

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Protein hydrolysates are composed of peptones and peptides, and their type depends on the biological source and manufacturing process. We studied the survival response of Salmonella enterica in the presence of casein, soy protein, and fish protein hydrolysates at refrigeration and freezing temperatures. Fish protein hydrolysate (FPH) was identified as the only capable hydrolysate of sustaining the viability of S. enterica for 60 days at refrigeration temperatures. None of the three hydrolysates were able to impart cryoprotection to S. enterica under freezing conditions. The survival rate of S. enterica in FPH was further enhanced by growing the inoculum on agar instead of broth. An optimization study using response surface methodology was also conducted to identify suitable concentrations of protein hydrolysates capable of maximizing the survival of S. enterica. The results of this study can be used to manage Salmonella-related food safety incidents by replacing animal-sourced with plant-sourced protein hydrolysates at the recipe development stage, as well as the use of FPH in microbiological growth media and the formulation of secondary reference materials. These results indicate that FPH produced by enzymatic hydrolysis of Stolephorus indicus at lower concentrations (5%) can serve as nutritive agents in culture media, contribute to long-term preservation, and can be used in the formulation of quantitative reference materials for Salmonella. [ABSTRACT FROM AUTHOR]

Whey protein derived bioactives, including a-lactalbumin, ß-lactoglobulin, bovine serum albumin, lactoferrin, transferrin, and proteose-peptones, have exhibited wide ranges of functional, biological and therapeutic properties varying from anticancer, antihypertensive, and antimicrobial effects. In addition, their functional properties involve gelling, emulsifying, and foaming abilities. For these reasons, this review article is framed to understand the relationship existed in between those compound levels and structures with their main functional, biological, and therapeutic properties exhibited either in vitro or in vivo. The impacts of hydrolysis mechanism and separation techniques in enhancing those properties are likewise discussed. Furthermore, special emphasize is given to multifunctional effects of whey derived bioactives and their future trends in ameliorating further food, pharmaceutical, and nutraceutical products. The underlying mechanism effects of those properties are still remained unclear in terms of activity levels, efficacy, and targeted effectiveness. For these reasons, some important models linking to functional properties, thermal properties and cell circumstances are established. Moreover, the coexistence of radical trapping groups, chelating groups, sulfhydryl groups, inhibitory groups, and peptide bonds seemed to be the key elements in triggering those functions and properties. PracticalApplication: Whey proteins are the byproducts of cheese processing and usually the exploitation of these food waste products has increasingly getting acceptance in many countries, especially European countries. Whey proteins share comparable nutritive values to milk products, particularly on their richness on important proteins that can serve immune protection, structural, and energetic roles. The nutritive profile of whey proteins shows diverse type of bioactive molecules like a-lactalbumin, ß-lactoglobulin, lactoferrin, transferrin, immunoglobulin, and proteose peptones with wide biological importance to the living system, such as in maintaining immunological, neuronal, and signaling roles. The diversification of proteins of whey products prompted scientists to exploit the real mechanisms behind of their biological and therapeutic effects, especially in declining the risk of cancer, tumor, and further complications like diabetes type 2 and hypertension risk effects. For these reasons, profiling these types of proteins using different proteomic and peptidomic approaches helps in determining their biological and therapeutic targets along with their release into gastrointestinal tract conditions and their bioavailabilities into portal circulation, tissue, and organs. The wide applicability of those protein fractions and their derivative bioactive products showed significant impacts in the field of emulsion and double emulsion stabilization by playing roles as emulsifying, surfactant, stabilizing, and foaming agents. Their amphoteric properties helped them to act as excellent encapsulating agents, particularly as vehicle for delivering important vitamins and bioactive compounds. The presence of ferric elements increased their transportation to several metal-ions in the same time increased their scavenging effects to metal-transition and peroxidation of lipids. Their richness with almost essential and nonessential amino acids makes them as selective microbial starters, in addition their richness in sulfhydryl amino acids allowed them to act a cross-linker in conjugating further biomolecules. For instance, conjugating gold-nanoparticles and fluorescentmaterials in targeting diseases like cancer and tumors in vivo is considered the cutting-edges strategies for these versatile molecules due to their active diffusion across-cell membrane and the presence of specific transporters to these therapeutic molecules. [ABSTRACT FROM AUTHOR]

Objectives: To develop an animal-derived component-free medium for Spodoptera frugiperda (Sf9) growth and green fluorescent protein (GFP) expression. Results: OSF9-ADCFM contained optimum concentrations of CDLC, YE and ST at 0.5% (v/v), 11.0 g/L, and 3.0 g/L, respectively. A mean viable cell concentration of 1.71 ± 0.14 × 105 cells/mL was obtained from 5 passages (P1-P5). The use of both peptones after 10 kDa ultrafiltration had a significant effect on Sf9 cell growth. Grace's insect medium with 10% FBS gave higher un-infected cell number than SF-900II and OSF9-ADCFM for 4.29 and 5.38 times, respectively. The average cell number of un-infected cells and GFP-fluorescent cells of SF-900II were higher than OSF9-ADCFM 1.25 and 7 times, respectively. Conclusion: In-house OSF9-ADCFM could support growth and GFP expression in Sf9 less than commercial SF-900II. However, it could lower the production cost at least 50% comparing to commercial SF-900II. The development of in- house OSF9-ADCFM would be continued to increase both cell numbers and protein expression in the next step. [ABSTRACT FROM AUTHOR]

This work investigated the suitability of using date syrup for producing bacterial cellulose (BC) by Gluconacetobacter xylinus (PTCC 1734). In the preliminary study, BC was produced in Hesterin-Schramm (HS) medium. The highest production yield was achieved after 12 days of cultivation at the initial pH of 8. Considering this result, BC was produced in modified HS media containing date syrup. In the modified HS1 (MHS1) medium, glucose was omitted, and in the modified HS2 (MHS2) medium, neither glucose nor peptone was present. Interestingly, the production yield in the modified media was about 75% higher than the production using HS medium. The amounts of BC produced using MHS1 and MHS2 media were obtained as 5.03 gL-1 and 5.17 gL-1, respectively. Structure analysis of these specimens indicated long fibrils, with diameters less than 70 nm. However, the crystallinity index of BC obtained from MHS1 media, containing peptone, was higher than that of BS produced in MHS2. [ABSTRACT FROM AUTHOR]

The pH of pre-enrichment media containing feed/ingredients can become acidic during incubation due to bacterial utilization of feed carbohydrates. This decrease in pH can result in cell injury or death, negatively impacting the detection of Salmonella. Our objective was to evaluate a new triple buffered peptone (TBP) against buffered peptone water (BPW) and lactose broth (LB) for the recovery of Salmonella from feed. Liquid cultures of nalidixic acid resistant strains of Salmonella (Enteritidis, Heidelberg, Kentucky or Typhimurium) were added to the pre-enrichment media alone, to pre-enrichment media containing feed or to artificially inoculated feed stored 1 or 7 d to evaluate the effect of the medium on the recovery of Salmonella. Three replicates per treatment were conducted. After incubation at 37 °C for 24 h, the pH of the medium was measured prior to plating onto brilliant green sulfa agar plates supplemented with 200 ppm nalidixic acid (BGSNA). Plates were incubated and evaluated for presence of typical Salmonella colonies. The experiment was replicated. TBP was observed to exhibit significantly better buffering capacity than BPW or LB. Additionally, TBP was able to recover Salmonella 100% of the time compared to BPW (97.9%) and LB (61.5%). TBP shows promise to maintain neutral pH during pre-enrichment which may allow for a more accurate detection of Salmonella in feed. [ABSTRACT FROM AUTHOR]

Peptones are one of the most expensive components of microbial culture media. The present study was conducted to test the usability of low-cost sheep wool peptone (SWP) as an organic nitrogen source in the production of six industrially important enzymes (lipase, amylase, tannase, pectinase, cellulase and invertase). SWP was prepared by alkaline hydrolysis and acid neutralization. Bacillus licheniformis and Aspergillus niger were selected as test microorganisms for enzyme production. To evaluate the efficacy of SWP in enzyme production, it was compared with commercial tryptone peptone (TP) in the shaking flask cultures of the test microorganisms. The optimum concentration of both SWP and TP was determined to be 8 g/L for the production of B. licheniformis-derived enzymes, but 6 g/L for the production of A. niger-derived enzymes. It was determined that SWP was superior to TP in the production of four enzymes (lipase, amylase, tannase and pectinase) of both B. licheniformis and A. niger. This is the first study about the usage of sheep wool protein hydrolysate (SWP) as an organic nitrogen source or a peptone in fermentative production of microbial enzymes. [ABSTRACT FROM AUTHOR]

Copyright of Food Research & Development is the property of Food Research & Development Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The fish processing industry generates a significant amount of waste, and the recycling of this waste is an issue of global concern. We sought to utilize the heads of cutlassfish (Trichiurus lepturus), which are typically discarded during processing, to produce peptone, which is an important source of amino acids for microbial growth and recombinant protein production. Cutlassfish head muscle (CHM) were isolated, and the optimal protease and reaction conditions for peptone production were determined. The resulting peptone contained 12.22 % total nitrogen and 3.19 % amino nitrogen, with an average molecular weight of 609 Da, indicating efficient hydrolysis of CHM. Growth assays using Escherichia coli have shown that cutlassfish head peptone (CP) supports similar or superior growth compared to other commercial peptones. In addition, when recombinant chitosanase from Bacillus subtilis and human superoxide dismutase were produced in E. coli, CP gave the highest expression levels among six commercial peptones tested. In addition, the expression levels of chitosanase and superoxide dismutase were 20 % and 32 % higher, respectively, in CP medium compared to the commonly used Luria-Bertani (LB) medium. This study demonstrates the potential of using cuttlassfish waste in the production of microbial media, thereby adding significant value to fish waste. The results contribute to sustainable waste management practices and open avenues for innovative uses of fish processing by-products in biotechnological applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in the paper. The authors declared that they don't have competing interests on this study., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

5-hydroxymethylfurfural (HMF) is a platform chemical that can be converted into a wide range of high-value derivatives. Industrially, HMF-based derivatives are synthesized via chemical catalysis. However, biocatalytic transformation has emerged as an attractive alternative. Significant advances have been made in the last years using isolated enzymes and whole-cell biocatalysts in HMF biotransformation. Nonetheless, one of the major bottlenecks is the cost of the process, mainly due to the microorganism growth substrate. In this work, biotransformation studies to transform HMF into 2,5-di(hydroxymethyl)furan (DHMF) were carried out with the fungus Fusarium striatum using low-cost protein hydrolysates. The protein hydrolysates were obtained from fines, an unexploited material produced during the rendering process of meat industry waste residues. Given the high content in the protein of fines, of around 46%, protein hydrolysis was optimized using two commercially available proteases, Alcalase 2.4 L and Neutrase 0.8 L. The maximum degree of hydrolysis (DH) achieved with Alcalase 2.4 L was 21.4% under optimal conditions of 5% E/S ratio, pH 8, 55 °C, and 24 h. On the other hand, Neutrase 0.8 L exhibited lower efficiency, and therefore, lower protein recovery. After optimization of the Neutrase 0.8 L process using the response surface methodology (RSM), the maximum DH achieved was 7.2% with the variables set at 15% E/S ratio, initial pH 8, 40 °C, and 10.5 h. Using these hydrolysates as a nitrogen source allowed higher sporulation of the fungus and, therefore, the use of a lower volume of inoculum (three-fold), obtaining a DHMF yield > 90%, 50% higher than the yield obtained when using commercial peptones. The presented process allows the transformation of animal co- and by-products into low-cost nitrogen sources, which greatly impacts the industrial feasibility of HMF biotransformation. [ABSTRACT FROM AUTHOR]

Ergosterol is an important provitamin in the present-day of industrial biotechnology. Seven yeast strains were obtained from the market of Basrah city and subjected to screening for their ergosterol production ability using liquid-state fermentation, the cultural conditions, and nutritional requirements for optimal production of ergosterol by Saccharomyces cerevisiae under laboratory conditions were determined. Y.6 is the best isolate of the yeast that produced ergosterol. It was identified as S. cerevisiae, with a similarity rate of 97% by using the Vitek2 device, this S. cerevisiae (Y.6) was further subjected to optimization conditions. The results showed that the best medium for production was yeast extract peptone dextrose broth. The effect of two cheaper carbon sources, molasses and date juice were investigated. Maximum ergosterol (0.55% ) was produced using a medium containing date juice, with a replacement ratio of 75%, an incubation time of 72 hours, pH 5, at a temperature of 30 °C, and an inoculation volume of 4 ml. The percentage of ergosterol was (0.47, 0.55, 0.74, 0.66, 0.68 and 0.78 %), respectively. [ABSTRACT FROM AUTHOR]

Characteristics and the use as culture media of protein hydrolysate from Locusta migratoria were determined in comparison with different peptones. After powdering, it was hydrolyzed chemically (acid hydrolysis) and obtained product Locust Peptone (LP). The contents of nitrogen, protein, fat, ash, total sugars, minerals and amino acids of LP were determined and it was seen that it has both organic and inorganic materials enough to use as a component of the medium. The effects of different concentrations added 20g/l glucose of LP on the growth of four test bacteria (Staphylococcus aureus, Bacillus subtilis, Pseudomonas putida and Escherichia coli) and test yeasts (Rhodotorula glutinis, Candida albicans, Saccharomyces cerevisiae) were investigated and it was found that the optimal concentration for bacteria and yeast are %0,6 and LP was compared with bacteriological peptone (BP), fish peptone (FP) and meat peptone (MP) .The obtained results with surface streaking and shaking culture procedures showed that LP yielded a little higher or equal FP and BP in both normal bacteria, but these values were lower than values obtained from MP. The results show that LP performed similar to or even better than commercial peptones as nitrogen sources for microorganisms growth. A new peptone has been developed from locust for microbiological media in the present study. [ABSTRACT FROM AUTHOR]

Background: The widespread usage of protein expression systems in Escherichia coli (E. coli) is a workhorse of molecular biology research that has practical applications in biotechnology industry, including the production of pharmaceutical drugs. Various factors can strongly affect the successful construction and stable maintenance of clones and the resulting biosynthesis levels. These include an appropriate selection of recombinant hosts, expression systems, regulation of promoters, the repression level at an uninduced state, growth temperature, codon usage, codon context, mRNA secondary structure, translation kinetics, the presence/absence of chaperons and others. However, optimization of the growth medium's composition is often overlooked. We systematically evaluate this factor, which can have a dramatic effect on the expression of recombinant proteins, especially those which are toxic to a recombinant host. Results: Commonly used animal tissue- and plant-based media were evaluated using a series of clones in pET vector, containing expressed Open Reading Frames (ORFs) with a wide spectrum of toxicity to the recombinant E. coli: (i) gfpuv (nontoxic); (ii) tp84_28—which codes for thermophilic endolysin (moderately toxic); and (iii) tthHB27IRM—which codes for thermophilic restriction endonuclease-methyltransferase (REase-MTase)—RM.TthHB27I (very toxic). The use of plant-derived peptones (soy peptone and malt extract) in a culture medium causes the T7-lac expression system to leak. We show that the presence of raffinose and stachyose (galactoside derivatives) in those peptones causes premature and uncontrolled induction of gene expression, which affects the course of the culture, the stability of clones and biosynthesis levels. Conclusions: The use of plant-derived peptones in a culture medium when using T7-lac hybrid promoter expression systems, such as Tabor-Studier, can lead to uncontrolled production of a recombinant protein. These conclusions also extend to other, lac operator-controlled promoters. In the case of proteins which are toxic to a recombinant host, this can result in mutations or deletions in the expression vector and/or cloned gene, the death of the host or highly decreased expression levels. This phenomenon is caused by the content of certain saccharides in plant peptones, some of which (galactosides) may act as T7-lac promoter inducer by interacting with a Lac repressor. Thus, when attempting to overexpress toxic proteins, it is recommended to either not use plant-derived media or to use them with caution and perform a pilot-scale evaluation of the derepression effect on a case-by-case basis. [ABSTRACT FROM AUTHOR]

An efficient protocol for direct plant regeneration inclusive of rooting and genetic fidelity testing via protocorm-like body (PLB) induction on nodal segments of Vanilla planifolia is presented. Effects of 16 different combinations of plant growth regulators, namely, benzyl aminopurine (BAP), zeatin and naphthalene acetic acid (NAA) were evaluated for PLB induction. BAP at a concentration of 1.5 mg/l together with 2 mg/l NAA in Murashige and Skoog (MS) medium was the most effective in inducing PLBs. Induced PLBs showed good proliferation on peptone supplemented media. Histological observation revealed the sub dermal origin of PLBs, gradually forming shoot apical meristem, shoot primordia and leaf primordia. Mature PLBs regenerated to form shoots on 20 media combinations tested for plantlet regeneration. Best induction rate of 5.08 shoots per PLB after eight weeks of culture was observed on MS medium containing 1 mg/l BAP and 1.5 mg/l NAA. NAA had a stimulatory effect on in vitro rooting with best response recorded on MS medium supplemented with 1 mg/l NAA. Genetic fidelity analysis of well-developed plantlets using inter sequence simple repeat (ISSR) markers revealed no change amongst the tested plants and their mother stocks. Direct regeneration of plantlets by induction of PLBs is an efficient alternative to routine micro-propagation via shoot tips/nodal explants for mass multiplication and germplasm conservation of this commercially important orchid species. [ABSTRACT FROM AUTHOR]

This study investigated the usability of sheep wool peptone (SWP) as an organic nitrogen source in production of pigments from the bacterium Serratia marcescens and the yeast Rhodotorula glutinis. SWP was prepared from sheep wool by KOH hydrolysis and H3PO4 neutralization. The potantial of SWP on pigment synthesis was compared with commercial tryptone peptone (TP) and proteose peptone (PP). The effectiveness of peptones on pigment synthesis was tested at different culture pHs and peptone concentrations in shaking flask culture. An initial medium pH of 7.0 and a peptone concentration of 6 g/L were found to be optimal for carotenoid synthesis in R. glutinis, but an initial culture pH of 8.0 and a peptone concentration of 8 g/L for prodigiosin synthesis in S. marcescens. In SWP, TP and PP‐based cultures; prodigiosin concentrations of 341, 175, and 302 mg/L; and carotenoid concentration of 94, 88, and 80 mg/L were reached. Novelty impact statement: Commercial peptones or protein hydrolysates are extensively used as organic nitrogen source in production of microbial pigments; however, high price of peptones restricts their use for this purpose. The present study revealed that protein hydrolysate prepared from sheep wool could be used as a peptone source in production of pigments from the yeast Rhodotorula glutinis and the bacterium Serratia marcescens. SWP was found to be superior to commercial peptones for production of both R. glutinis and S. marcescens pigments. Usability of wool protein hydrolyzate as an organic nitrogen source or peptone in production of microbial pigments was tested for the first time in the present study. [ABSTRACT FROM AUTHOR]

The increased production of blue foods has resulted in the waste of blue foods by-products. Converting blue foods by-products into useable protein hydrolysates and bioactive peptides can improve the utilization of by-products. At the same time, the rich biological activities of bioactive peptides can be used in a wide range of applications. This article reviews the current research status of protein hydrolysates from blue foods, including preparation, isolation, identification and applications. The biological activities of protein hydrolysates from blue foods by-products have rich application prospects. Bioactive peptides can be utilized for their antioxidant, antibacterial, and antifreeze properties to improve the quality of food. B ioactive peptides have the gelling effect, and their rich nutritional properties can be used as peptones. Furthermore, conjugating bioactive peptides with polyphenols can enhance their biological activities. Adding bioactive peptides to foods can also enhance food properties. The metal-binding ability of bioactive peptides can enhance the stability of chelated calcium and chelated zinc. Therefore, bioactive peptides from blue foods by-products can be applied in food and pharmaceutical industries, but their safety and utilization need to be further explored. [Display omitted] • Protein hydrolysates from blue foods by-products have a wide range of applications. • Bioactive peptides can exploit their properties to improve food quality. • Utilization of blue foods by-products can increase economic benefits. [ABSTRACT FROM AUTHOR]

Attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy has been used to probe the binding of bacteria to hematite (α-Fe2O3) and goethite (α-FeOOH). In situ ATR-FTIR experiments with bacteria (Pseudomonas putida, Pseudomonas aeruginosa, Escherichia coli), mixed amino acids, polypeptide extracts, deoxyribonucleic acid (DNA), and a suite of model compounds were conducted. These compounds represent carboxyl, catecholate, amide, and phosphate groups present in siderophores, amino acids, polysaccharides, phospholipids, and DNA. Due in part to the ubiquitous presence of carboxyl groups in biomolecules, numerous IR peaks corresponding to outer-sphere or unbound (1400 cm(-1)) and inner-sphere (1310-1320 cm(-1)) coordinated carboxyl groups are noted following reaction of bacteria and biomolecules with α-Fe2O3 and α-FeOOH. However, the data also reveal that the presence of low-level amounts (i.e., 0.45-0.79%) of biomolecular phosphorous groups result in strong IR bands at ∼1043 cm(-1), corresponding to inner-sphere Fe-O-P bonds, underscoring the importance of bacteria associated P-containing groups in biomolecule and cell adhesion. Spectral comparisons also reveal slightly greater P-O-Fe contributions for bacteria (Pseudomonad, E. coli) deposited on α-FeOOH, as compared to α-Fe2O3. This data demonstrates that slight differences in bacterial adhesion to Fe oxides can be attributed to bacterial species and Fe-oxide minerals. However, more importantly, the strong binding affinity of phosphate in all bacteria samples to both Fe-oxides results in the formation of inner-sphere Fe-O-P bonds, signifying the critical role of biomolecular P in the initiation of bacterial adhesion.

Endoglucanase producing bacteria were isolated from Egyptian soils and the most active bacterial strain was identified as Bacillus subtilis strain Fatma/1. Plackett–Burman statistical design was carried out to assess the effect of seven process variables on endoglucanase production. Carboxymethyl cellulose (CMC), yeast extract and peptone were the most significant variables that enhanced the endoglucanase production and thus were selected for further optimization using face-centered central composite design. The highest yield of endoglucanase (32.37 U/mL) was obtained in run no. 9, using 18 g/L CMC, 8 g/L peptone, 7 g/L yeast extract and 0.1 g/L FeSO4.7H2O. The optimized medium showed about eightfold increase in endoglucanase production compared to the unoptimized medium. The produced crude enzyme was further purified by ammonium sulfate precipitation, then DEAE-Sepharose CL6B column. The purified enzyme was shown to have a molecular weight of 37 kDa. The enzyme showed maximum activity at pH 8.0, temperature of 50 °C, incubation time of 60 min. The half-life time (T1/2) was 139.53 min at 50 °C, while being 82.67 min at 60 °C. Endoglucanase at concentration of 12 U/mL effectively removed 84.61% of biofilm matrix of Pseudomonas aeruginosa with marked reduction in carbohydrate content of the biofilm from 63.4 to 7.9 μg. [ABSTRACT FROM AUTHOR]

In this study, chicken peptone was produced by hydrolysing inedible parts derived from chickens using endo‐protease and exo‐protease. The usefulness of chicken peptone as a nutrient source for bacteria was evaluated in comparison with other commercially produced peptones (animal, soy and casein‐derived peptone). Escherichia coli and Bacillus subtilis were used as test strains to determine the effect of peptones from different sources on their growth ability. Both bacteria were successfully cultured in chicken peptone solution, which is similar to peptone solution containing commercial peptones apart from animal peptone. In chemical analysis, chicken peptone contained 12·0% nitrogen; this was similar to the nitrogen content from other commercial peptone sources, except for the 9·0% nitrogen found in soy peptones. The molecular weight of the peptone was determined by gel filtration chromatography, and those of all peptone, except animal‐derived peptone, were found to be <5000 Da. In addition, when B. subtilis was cultured in a medium containing chicken peptone, it was shown that the protease activity was highest as compared with other commercial peptones. From these results, it is suggested that chicken peptone can be utilized for microbial culture, and this is an effective method to reuse chicken waste. [ABSTRACT FROM AUTHOR]

• Viscera-containing salmon peptones were superior to meat-based peptones. • Viscera-containing peptones were superior for nutrient-demanding lactic acid bacteria. • Zinc was limiting factor in peptones based on head and backbones, without viscera. • High-throughput screening enabled tests of a high number of peptones and strains. Twelve marine peptones prepared from rest raw materials (RRM) from farmed salmon have been evaluated as nutrient sources in growth media for industrial microorganisms. The peptones were prepared from head and backbones, or from head, backbones and viscera, using different proteases and one or two-step hydrolysis. Growth was determined as optical density using a high-throughput robotic system, allowing for testing of a large number of peptones and microorganisms. For two Lactobacillus -strains tested, the peptones were the only nitrogen source, while for four aerobic bacteria and yeasts, the peptones were assessed as a source of growth factors, with inorganic nitrogen in excess in the media. The peptones containing viscera resulted in higher cell yields than those without, and high growth rates were maintained to higher cell densities. The viscera-containing peptones were better than meat-based peptones, and equally good as yeast extract. The differences between the performance of peptones with and without viscera could be explained by the mineral content and the degree of hydrolysis. Since peptones based on farmed salmon RRM can be provided in large quantities with a stable quality, they should be further explored as a nutrient source for the fermentation industry. [ABSTRACT FROM AUTHOR]

Workers' task specialization and division of labor are critical features of social insects' ecological success. It has been proposed that the division of labor relies on response threshold models: individuals varying their sensitivity (and responsiveness) to biologically relevant stimuli and performing a specific task when a stimulus exceeds an internal threshold. In this work, we study carbohydrate and protein responsiveness and their relation to worker task specialization in Vespula germanica, an invasive social wasp. The sucrose and peptone responsiveness of two different subcastes, preforagers and foragers, was determined by stimulating the antenna of the wasps with increasing concentrations of the solution and quantifying whether each concentration elicited a licking response. We studied responsiveness in five different ways: (1) response threshold, (2) concentration 50 (concentration to which at least 50% of wasps responded), (3) maximum response, (4) mean scores and (5) median scores. Our results suggest that V. germanica foragers are more sensitive to sucrose (lower thresholds) than preforager workers. However, we found no differences for peptone thresholds (i.e., a protein resource). Nonetheless, this is the first study to investigate response thresholds for protein resources. The intercaste variation in sucrose responsiveness shown in our work contributes to the existing knowledge about response threshold theory as a mechanism for task specialization observed in V. germanica., (© 2023 Institute of Zoology, Chinese Academy of Sciences.)

Industrial waste, such as crude glycerol, was used for vitamin K2 by B. subtilis Z-15. Crude glycerol could be used instead of pure glycerin for vitamin K2 production. The combination of soybean peptone and yeast extract was more conducive to the synthesis of vitamin K2. The optimal composition of medium was obtained by response surface methodology. The results indicated that the optimal medium was as follows: 6.3% crude glycerol, 3.0% soybean peptone concentration and 5.1 g/L yeast extract. Under the optimal culture medium, vitamin K2 production was increased to 45.11 ± 0.62 mg/L. The fermentor test further proved that the use of crude glycerol affected neither the synthesis of vitamin K2 nor the growth of B. subtilis. These investigations could lay a foundation for reducing the pollution of crude glycerol, exploring a late model for vitamin K2 cleaner production. [ABSTRACT FROM AUTHOR]

The present study aims to detection optimal conditions of production of dextranase enzyme from isolate of B. subtilis Z2. Eight carbonic sources were represented by Dextran, Molasses, fructose, sucrose, glucose, Lactose, CMC and Arabinose) at concentration of 0.5% for each source. It was found that the best was represented by Molasses carbonic which showed higher activity and qualitative activity of 7.11 units / ml and 83.01 units / mg. The nitrogen sources were selected, including yeast extract, peptone, yeast extract with peptone, gelatin, meat extract, Ammonium sulphate, Potassium nitrate and Ammonium chloride. These sources were added at a concentration of 0.5% to the production medium. The Peptone with yeast extract source was the best of used nitrogenic sources at concentration of 1.2%, which showed higher activity and qualitative activity at 8.89 units / ml and 85.5 units / mg. The best hydrogen number was 7. The size of inoculums of 3 x 107 c.f.u. was the best which showed higher activity and qualitative activity of 21.702 units/ ml and 301.29 units/ mg. there incubation which 44 hours showed higher activity and qualitative activity of 32.934 units / ml and 633.52 units / mg. [ABSTRACT FROM AUTHOR]

The influence of an alternating current (AC) frequency from 50 to 20,000 Hz at 30 V/cm using ohmic heating on the inactivation of E. coli O157:H7 in buffer peptone water (BPW) and pomelo juice was investigated. Frequency affected bacterial reduction in both BPW and pomelo juice with the same trend, and the most efficient reductions were obtained at 60 and ≥ 500 Hz. Besides, the resistance of E.coli O157:H7 was investigated. BPW and pomelo juice were treated at different temperatures (62-71 °C) for various times (0-30 s) by ohmic heating (OH) and compared with conventional heating (CH). The technical parameters of OH were an electric field strength of 30 V/cm and frequencies of 60 and 500 Hz. At each temperature, the decimal reduction time (D) and the decimal reduction temperature (z) were determined. Microorganism reduction was significantly higher (P < 0.05) with OH than with CH, and there was no significant difference between the juice samples treated by OH at 60 and 500 Hz. For OH at 60 Hz, the D values of E. coli O157:H7 in pomelo juice were 59.0, 27.3, 10.3, and 3.6 s at temperatures of 60, 62, 65, and 68 °C, with a z value of 6.7 °C. For CH, the D values were 35.4, 14.3, 8.2, and 2.9 s, with a z value of 8.6 °C. From the calculated D and z values, a processing schedule for the pasteurization of pomelo juice can be estimated. Observing the bacterial cells by transmission electron microscopy (TEM) showed considerable changes in the morphology of the bacterial cells with OH, which might be the cause of cell death. These results demonstrated that the electric field obtained with OH yields additional microbial destruction. As a result, the time and temperature required for bacterial inactivation can be reduced, diminishing the negative heat effects of pasteurization on the food products. [ABSTRACT FROM AUTHOR]

Peptones were extracted from the head by-products of grouper (Epinephelus fuscoguttatus) and parrotfish (Scarus javanicus) with different acid combinations. The peptones showed significant differences on yield, solubility, color, bacterial growth profile, and biomass production (P < 0.05). The yield of parrotfish peptone (PFP) and grouper fish peptone (GFP) ranged from 3.27% to 3.45% and 4.61% to 5.70%, respectively. The major component of both peptones was protein varied between 83.80% and 86.67%. The whiteness of peptone samples was in the range of 33.56% to 60.06% with the highest in GFP by adding 1.5% (v/m) of propionic/formic acid (1:2, v/v). Although the solubility of peptone samples was slightly lower than the commercial peptone, both PFP and GFP samples exhibited better performance in the growth of bacteria (Escherichia coli and Staphylococcus aureus). The biomass production of PFP and GFP increased significantly when compared that to commercial peptone. The PFP and GFP samples contained high values of the amino acids (glycine, glutamic acid, proline, and alanine). The results revealed that grouper and parrotfish head by-product are potential material for bacterial peptone. [ABSTRACT FROM AUTHOR]

Comparability stability studies of a live Newcastle Disease LaSota vaccine were conducted post freeze-drying and during storage at 5±2, 25±2 and 37±1 °C to demonstrate the equivalence/inequivalence of stability profiles of vaccines stabilized with peptone (reference), trehalose and starch derivatives (acetylated xerogel and carboxymethylated) from Plectranthus esculentus tubers. Variations in moisture content during storage at 5±2 °C; physical collapse/shrinkage, partial microcollapse, and hydrophilicity of lyophilisates were prominent in starch stabilized vaccines without additives. Using the mean embryo infective dose (EID 50 ) test, the derivatives and peptone stabilized vaccines had < 0.5 logEID 50 loss in titre during freeze-drying. At the storage temperatures of 5±2, 25±2 and 37±1 °C, using peptone, acetylated xerogel starch, carboxymethylated starch, and trehalose, the average shelf lives of the vaccines were 23-55, 21-26, and 2.6-4.9 months respectively. Acetylated xerogel and carboxymethylated derivatives of Plectranthus esculentus tuber starch with/without additives were able to keep the live ND LaSota vaccine stable during freeze-drying at 1-3 % w / v . The stability of all the vaccines declined as storage temperatures increased. The acetylated xerogel stabilized vaccines were more stable than all of the others at 25±2 and 37±1 °C temperatures., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

Respiratory tract infections (RTIs) are a common cause of mortality and morbidity in the human population. The overuse of antibiotics to overcome such infections has led to antibiotic resistance. The emergence of multidrug resistant bacteria is necessitating the development of novel therapeutic techniques in order to avoid a major global clinical threat. Our study aims to investigate the potential of tryptone stabilised silver nanoparticles (Ts-AgNPs) on planktonic and biofilms produced by Klebsiella pneumoniae ( K. pneumoniae ) and Pseudomonas aeruginosa ( P. aeruginosa ). The MIC 50 of Ts-AgNPs was found to be as low as 1.7 μg ml -1 and 2.7 μg ml -1 for K. pneumoniae and P.aeruginosa respectively. Ts-AgNPs ability to alter redox environment by producing intracellular ROS, time-kill curves showing substantial decrease in the bacterial growth and significantly reduced colony forming units further validate its antimicrobial effect. The biofilm inhibition and eradication ability of Ts-AgNPs was found to be as high as 93% and 97% in both the tested organisms. A significant decrease in the eDNA and EPS quantity in Ts-AgNPs treated cells proved its ability to successfully distort the matrix and matured biofilms. Interestingly Ts-AgNPs also attenuated QS-induced virulence factors production. This study paves way to develop Ts-AgNPs as novel antibiotics against RTIs causing bacterial biofilms., (© 2024 IOP Publishing Ltd.)

Background: Hermetia illucens (HI), commonly known as the black soldier fly, has been recognized for its prowess in resource utilization and environmental protection because of its ability to transform organic waste into animal feed for livestock, poultry, and aquaculture. However, the potential of the black soldier fly's high protein content for more than cheap feedstock is still largely unexplored., Methods: This study innovatively explores the potential of H. illucens larvae (HIL) protein as a peptone substitute for microbial culture media. Four commercial proteases (alkaline protease, trypsin, trypsase, and papain) were explored to hydrolyze the defatted HIL, and the experimental conditions were optimized via response surface methodology experimental design. The hydrolysate of the defatted HIL was subsequently vacuum freeze-dried and deployed as a growth medium for three bacterial strains ( Staphylococcus aureus , Bacillus subtilis , and Escherichia coli ) to determine the growth kinetics between the HIL peptone and commercial peptone., Results: The optimal conditions were 1.70% w/w complex enzyme (alkaline protease: trypsin at 1:1 ratio) at pH 7.0 and 54 °C for a duration of 4 h. Under these conditions, the hydrolysis of defatted HIL yielded 19.25% ±0.49%. A growth kinetic analysis showed no significant difference in growth parameters ( μ max , X max , and λ ) between the HIL peptone and commercial peptone, demonstrating that the HIL hydrolysate could serve as an effective, low-cost alternative to commercial peptone. This study introduces an innovative approach to HIL protein resource utilization, broadening its application beyond its current use in animal feed., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (©2024 Liu et al.)

The long-term existence of peptone can breed a large number of bacteria and cause the eutrophication of municipal wastewater. Thus, removing peptone in the wastewater is a major challenge facing the current industry. This study used cationic and anionic lignin polymers, i.e., kraft lignin-[2-(methacryloyloxy)ethyl] trimethylammonium methyl sulfate (cationic lignin polymer, CLP) and kraft lignin-acrylic acid (anionic lignin polymer, ALP), as flocculants to eliminate peptone from model wastewater in the single and dual component systems. The affinity of peptone for ALP or CLP was assessed by quartz crystal microbalance with dissipation, X-ray photoelectron spectroscopy, contact angle, and vertical scan analyzer. Results illustrated that the adsorption effect of CLP for peptone was significantly superior to that of ALP owing to the stronger vital interaction between cationic polymer and peptone molecules. Based on destabilization and sedimentation analyses, introducing CLP triggered the preliminary flocculation of peptone via bridging action, as indicated by a considerable increment in the destabilization index (from 1.1 to 10.6). Moreover, peptone adsorbed more on the CLP coated surface than on the ALP coated one (14.8 vs 5.4 mg/m 2 ), while ALP facilitated its further adsorption in the dual polymer system. This is because CLP adsorbed a part of peptone molecules on its surface. Then, ALP entrapped the unattached peptone onto the CLP coated surface through electrostatic interaction. Compared with the single polymer system, mixing ALP and CLP subsequently into the peptone solution in the dual system generated larger size aggregates (mean diameter of 6.1 μm) and made the system destabilization (Turbiscan stability index up to 58.1), thereby yielding more flocculation and sedimentation. Finally, peptone was removed successfully from simulated wastewater with a turbidity removal efficiency of 92.5%. These findings confirmed that the dual-component system containing two lignin-derived polymers with opposite charges could be viable for treating peptone wastewater., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Pedram Fatehi reports financial support was provided by Lakehead University. Kang Kang is the coauthor of this paper, but also a guest editor of this journal., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

How do pathogens affecting the same host interact with each other? We evaluated here the types of microbe-microbe interactions taking place between Streptomyces scabiei and Phytophthora infestans, the causative agents of common scab and late blight diseases in potato crops, respectively. Under most laboratory culture conditions tested, S. scabiei impaired or completely inhibited the growth of P. infestans by producing either soluble and/or volatile compounds. Increasing peptone levels correlated with increased inhibition of P. infestans. Comparative metabolomics showed that production of S. scabiei siderophores (desferrioxamines, pyochelin, scabichelin, and turgichelin) increased with the quantity of peptone, thereby suggesting that they participate in the inhibition of the oomycete growth. Mass spectrometry imaging further uncovered that the zones of secreted siderophores and of P. infestans growth inhibition coincided. Moreover, either the repression of siderophore production or the neutralization of their iron-chelating activity led to a resumption of P. infestans growth. Replacement of peptone by natural nitrogen sources such as ammonium nitrate, sodium nitrate, ammonium sulfate, and urea also triggered siderophore production in S. scabiei. Interestingly, nitrogen source-induced siderophore production also inhibited the growth of Alternaria solani, the causative agent of the potato early blight. Overall, our work further emphasizes the importance of competition for iron between microorganisms that colonize the same niche. As common scab never alters the vegetative propagation of tubers, we propose that S. scabiei, under certain conditions, could play a protective role for its hosts against much more destructive pathogens through exploitative iron competition and volatile compound production., (© The Author(s) 2024. Published by Oxford University Press.)

In nature, protozoa play a major role in controlling bacterial populations. This paper proposes a microfluidic device for the study of protozoa behaviors change due to their chemotactic response in the presence of bacterial cells. A three-channel microfluidic device was designed using a nitrocellulose membrane into which channels were cut using a laser cutter. The membrane was sandwiched between two glass slides; a Euglena suspension was then allowed to flow through the central channel. The two side channels were filled with either, 0.1% peptone as a negative control, or a Listeria suspension respectively. The membrane design prevented direct interaction but allowed Euglena cells to detect Listeria cells as secretions diffused through the nitrocellulose membrane. A significant number of Euglena cells migrated toward the chambers near the bacterial cells, indicating a positive chemotactic response of Euglena toward chemical cues released from Listeria cells. Filtrates collected from Listeria suspension with a series of molecular weight cutoffs (3k, 10k and 100k) were examined in Euglena chemotaxis tests. Euglena cells were attracted to all filtrates collected from the membrane filtration with different molecular weight cutoffs, suggesting small molecules from Listeria might be the chemical cues to attract protozoa. Headspace volatile organic compounds (VOC) released from Listeria were collected, spiked to 0.1% peptone and tested as the chemotactic effectors. It was discovered that the Euglena cells responded quickly to Listeria VOCs including decanal, 3,5- dimethylbenzaldehyde, ethyl acetate, indicating bacterial VOCs were used by Euglena to track the location of bacteria. [ABSTRACT FROM AUTHOR]

The preservation of biological samples for an extended time period of days to weeks after initial collection is important for the identification, screening, and characterization of bacterial pathogens. Traditionally, preservation relies on cold-chain infrastructure; however, in many situations this is impractical or not possible. Thus, our goal was to develop alternative bacterial sample preservation and transport media that are effective without refrigeration or external instrumentation. The viability, nucleic acid stability, and protein stability of Bacillus anthracis Sterne 34F2, Francisella novicida U112, Staphylococcus aureus ATCC 43300, and Yersinia pestis KIM D27 (pgm-) was assessed for up to 28 days. Xanthan gum (XG) prepared in PBS with L-cysteine maintained more viable F. novicida U112 cells at elevated temperature (40°C) compared to commercial reagents and buffers. Viability was maintained for all four bacteria in XG with 0.9 mM L-cysteine across a temperature range of 22–40°C. Interestingly, increasing the concentration to 9 mM L-cysteine resulted in the rapid death of S. aureus. This could be advantageous when collecting samples in the built environment where there is the potential for Staphylococcus collection and stabilization rather than other organisms of interest. F. novicida and S. aureus DNA were stable for up to 45 days upon storage at 22°C or 40°C, and direct analysis by real-time qPCR, without DNA extraction, was possible in the XG formulations. XG was not compatible with proteomic analysis via LC-MS/MS due to the high amount of residual Xanthomonas campestris proteins present in XG. Our results demonstrate that polysaccharide-based formulations, specifically XG with L-cysteine, maintain bacterial viability and nucleic acid integrity for an array of both Gram-negative and Gram-positive bacteria across ambient and elevated temperatures. [ABSTRACT FROM AUTHOR]

Hurdle technology, in which preservation techniques are combined, has been of interest to scientists aiming to ensure microbiological food safety. We investigated the synergistic effect of UV-C irradiation and ohmic heating on the inactivation of foodborne pathogens. UV-C irradiation and ohmic heating were applied to buffered peptone water and tomato juice inoculated with pathogens simultaneously or sequentially. A synergistic bactericidal effect of the simultaneous treatment was observed against Escherichia coli O157:H7, Salmonella Typhimurium and Listeria monocytogenes. For example, the reductions (log CFU/ml) in E. coli O157:H7 by UV-C irradiation, ohmic heating and simultaneous treatment in tomato juice were 0.48, 1.84 and 3.83, respectively. Additive effect was observed for cell membrane damage and lipid oxidation values with the simultaneous treatment Therefore, the proposed synergistic bactericidal mechanism by the simultaneous treatment consists of an acceleration of lipid oxidation, which results in an additive effect on cell membrane pore formation. Sequential treatment of UV-C irradiation after ohmic heating showed the least antibacterial effect in buffered peptone water. On the other hand, the reductions levels of all three pathogens in tomato juice were not significantly different between the two treatments regardless of the sequence. The color and lycopene content of tomato juice were not significantly deteriorated by either ohmic heating or the simultaneous treatment. Therefore, the combination treatment of UV-C irradiation and ohmic heating including simultaneous and sequential treatments, and regardless of treatment sequence, can be used as an effective hurdle technology ensuring microbiological safety in juice products. • A synergistic bactericidal effect of a combination treatment was observed. • Cell membrane damage resulting from membrane lipid oxidation was identified. • Treatment sequence had significant effect in BPW but not in juice product. • Quality of tomato juice was not deteriorated by the combination treatment. [ABSTRACT FROM AUTHOR]

Astaxanthin is a valuable carotenoid pigment, which has been extensively used in various industries. In this study, Rhodosporidium toruloides was first used as a new microbial source for producing natural astaxanthin. Various carbon, nitrogen, and mineral sources were evaluated for their effect on astaxanthin production of R. toruloides. Response surface methodology (RSM) was then used to optimize the medium compositions for maximizing the astaxanthin concentration. Among the examined nutrients, glucose, peptone, and KH2PO4 were the most efficient carbon, nitrogen, and mineral source for astaxanthin production, respectively. Through RSM, a maximum astaxanthin concentration of 927.11 μg l-1 was obtained by using Hansen broth containing 83.74 g l-1 glucose, 20.01 g l-1 peptone, and 6.19 g l-1 KH2PO4. This study suggested that R. toruloides is a promising candidate to produce natural astaxanthin. [ABSTRACT FROM AUTHOR]

Abstract In recent years, the potential application of plasma-activated water (PAW) in the food industry has received increasing attention as a promising alternative to traditional sanitizers. The objective of this work was to evaluate the effect of organic matters in the form of beef extract or peptone on the inactivation efficacy of PAW against Escherichia coli O157:H7 and Staphylococcus aureus. PAW was mixed with beef extract or peptone (final concentration: 0–5.0 g/L) and the mixture was allowed to stand at room temperature for 15 min. Subsequently, 100 μL of each bacterial suspension was treated with 900 μL of the PAW/organic matters solutions at room temperature for another 6 min. The results showed that PAW treatment without organic matters could effectively inactivate the tested bacteria, resulting in 3.70-and 2.32-log reduction of E. coli O157:H7 and S. aureus in comparison to the control group, respectively. Beef extract or peptone severely quenched the inactivation efficacy of PAW against E. coli O157:H7 and S. aureus in a dose-dependent way. The addition of beef extract and peptone significantly decreased the oxidation-reduction potential and NO 2 − concentration of PAW, increased the pH values of PAW in a dose-dependent manner (p < 0.05), but did not significantly affect its hydrogen peroxide (H 2 O 2) content (p > 0.05). Thus, more attention should be paid to the effect of interfering substances on the disinfection efficacy of PAW before its practical application. Highlights • PAW can effectively inactivate E. coli O157:H7 and S. aureus in suspension. • Beef extract and peptone weaken the inactivation efficacy of PAW. • Organic matters affect the physicochemical attributes of PAW. • It is essential to remove organic matters prior to application of PAW. [ABSTRACT FROM AUTHOR]

Abstract This study reports the effects of dilutions in distilled water, 0.85% saline, 0.10% peptone water and phosphate-buffered saline on the viability of Alicyclobacillus acidoterrestris. Only peptone water caused a significant underestimation of viable populations of vegetative cells. Effects of temperature and pH on the growth kinetics of A. acidoterrestris in yeast starch glucose (YSG) media were characterized using a two-factored Central Composite Design (CCD). Response Surface Methodology was applied to quantify their influences on lag time, growth rate, and population change. Rates ranged from −0.37 (inactivating) to 1.07 (growth), while population change varied from −3.11 to 2.89 log. Values significantly fitted into a linear model for the growth rate response and a quadratic model for the population change response. pH was observed to be the significant factor affecting the response variables, having significant quadratic effects. Model validation with temperature and pH combinations unique from the CCD showed that predictions were within acceptable error margins for the population change model, while the growth rate model exhibited limited success rate. The results obtained in this study provide information on growth behaviors of A. acidoterrestris in standard media and can be further used in researches dealing with its maintenance and propagation. Highlights • Peptone water significantly underestimated viable vegetative cells. • Rates ranged from that of inactivation to growth. • Significant models for growth rate and population change were observed. • Only pH affected growth kinetic parameters significantly. • Model validation with unique temperature-pH combinations showed acceptable predictive efficacy for population change. [ABSTRACT FROM AUTHOR]

Objectives: Single chamber air cathode microbial fuel cells (MFCs) were investigated with sodium-acetate and peptone as test substrates to assess the potential for application as biosensor to determine the concentration of biodegradable organics in water/wastewater samples. Results: MFCs provided well-reproducible performance at high (> 2000 mg COD l−1—Chemical Oxygen Demand) acetate concentration values. Current in the cells proved to be steady from 25 to 35 °C, significant decrease was, however, revealed in the current below 20 °C. Direct calculation of non-toxic biodegradable substrate concentration in water/wastewater from the current in MFCs is possible only in the non-saturated substrate concentration range due to the Monod-like dependence of the current. This range was determined by a fitted and verified Monod-based kinetic model. Half saturation constant (KS) values were calculated at 30 °C applying different external resistance values (100 Ω, 600 Ω and 1000 Ω, respectively). In each case KS remained below 10 mg COD l−1. Conclusions: Biosensors with this particular MFC design and operation are potentially applicable for detecting as low as 5 mg COD l−1 readily biodegradable substrates, and measuring the concentration of these substances up to ~ 50–70 mg COD l−1. [ABSTRACT FROM AUTHOR]

Highlights • Fish discards were integrally valorised and a whole of bioproducts were obtained. • Fish mince, gelatins, oils and fish protein hydrolysates (FPH) were produced. • Culture media with peptones from FPH were evaluated for P. accidilactici growth. • Those alternative media reduced bacterial productions between 2–5 folds. Abstract In the present work, we have developed a set of sequential and complementary alternatives to valorise five fish discards in order to recover and produce fish mince, oils, gelatins, fish protein hydrolysates (FPHs) with antioxidant and antihypertensive properties and marine peptones. In this last case, microbial bioconversion of marine peptones was studied by Pediococcus acidilacti growth, a well-known valuable lactic acid bacterium, and the concomitant production of lactic acid and pediocin SA-1. Highly digestible FPHs with a good quality of amino acids composition and antioxidant and antihypertensive properties were easily produced. In the same bioprocess, fish oils with a healthy ω-3/ ω-6 ratio were also isolated. The use of peptones derived from FPHs as bacterial media nutrient (source of organic nitrogen) led to reduction of bioproductions costs between 2–5 folds in comparison with commercial culture medium. [ABSTRACT FROM AUTHOR]

Chromium pollution has grave consequences and can cause serious damage to biological systems. Recently, polyamines have received significant attention due to their biotechnological interests. This study is aiming to test the effect of putrescine on hexavalent chromium [Cr(VI)] removal by Wickerhamomyces anomalus and cell surface physicochemical properties of this strain. The experiment was conducted in modified yeast extract, peptone, and glucose medium contaminated with 50 mg/L Cr(VI) and treated with putrescine at 0 (control), 1, and 10 mM. Results showed that putrescine enhanced Cr(VI) removal potential, accompanied by an increased hydrophobicity and electron acceptor character and a decreased electron donor character of surface cells. This putrescine action was dependent on its concentration with a higher effect at 10 mM. At this concentration, scanning electron microscope/energy dispersive X-ray analysis showed a modification of the chemical composition and a high concentration of nitrogen on yeast cell wall. Sorption data were modeled using the pseudofirst-order and pseudosecond-order equations. Results indicated that a pseudosecond-order kinetic model could better describe the metal sorption kinetics by W. anomalus cells at different putrescine concentrations. This work highlights the possibility of enhancement of wastewater treatment, especially heavy metal uptake, by modifying cell surface characteristics. [ABSTRACT FROM AUTHOR]

An experiment was conducted to investigate the best conditions for xylanase enzyme production from the local isolation Bacillus subtilis strain RS1 using xylene extracted from the papyrus. The results showed that the highest effectiveness of xylanase was obtained by using 0.5% xylene at 2800 ml/ml. Yeast extract and peptone were the best nitrogen sources where the enzymatic activity reached 2800 units /mL and the best temperature for xylanase production was 37°C and pH of 6 with cycles number of 150/min and vaccine size 107 cells/ml where the enzyme effectiveness reached 2807, 2806, 2808 and 2800 units/ml, respectively. [ABSTRACT FROM AUTHOR]

Abstract The white laccase was produced from Myrothecium verrucaria ITCC-8447 under submerged fermentation. The media components were optimized by response surface methodology (CCD-RSM). The nutritional components (glucose and peptone) and physical parameters (pH and temperature) were optimized by response surface methodology for enhanced laccase production by Myrothecium verrucaria ITCC-8447. The enzyme activity under optimum condition exhibited 1.45 fold increases in laccase activity. The white laccase was subjected to ion exchange chromatography with 6 fold purification. The molecular weight of white laccase was ~63–75 kDa as estimated by SDS-PAGE followed by the activity staining with ABTS where green bands confirmed the presence of laccase. The enzyme was stable over an alkaline pH range of 7–9 and the temperature range of 30–40 °C. The characterization of white laccase was done by CD spectra, UV–visible absorption, FTIR and XRD. The K m and V max values of the purified laccase were 2.5 mM and1818.2 μmol/min/L. The delignification capability of the white laccase was determined by reduction in Kappa number (58.8%) and Klason lignin (64.7%) of wheat straw after 12 h of incubation. Further the delignification was confirmed FTIR and XRD. Graphical abstract Unlabelled Image Highlights • The process optimization of white laccase using CCD-RSM from Myrothecium verrucaria ITCC-8447 • Purification of white laccase and its characterization by CD, UV-spectra, FTIR and XRD • First report on white laccase for the efficient delignification of agroresidues: a step towards "Green and Clean Environment" [ABSTRACT FROM AUTHOR]

Kaoliang is a refreshing fragranced type of Chinese spirits with slight apple fragrance that comes from ethyl acetate (EA). Special aromas are produced by esterification microorganisms, which affect the taste and quality of the wine. In this study, new yeast strains were isolated from yellow water, a by-product during fermentation process. Meanwhile, the optimal culture condition was determined for its growth and EA production. Three new strains, Kazachstaniaexigua, Candida humilis and Saccharomyces cerevisiae were identified from yellow water. Among these strains, S. cerevisiae S5 was the new and dominant strain. Results from response surface methodology showed that S. cerevisiae S5 produced 161.88 ppm of EA, in the medium with 4.91% yeast extract, 9.82% peptone, and 20.91% glucose after 96 hours of cultivation at 27.53°C. GC analysis showed that aroma compounds, such as EA, isoamyl acetate and 2-phenylethanol increased from the sample of optimal condition when compared to the one from initial fermentation condition. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A method to identify and quantify Histamine contamination in Gentamicin medicinal products and active pharmaceutical ingredients by QTOF LC/MS. • Hydrophilic interaction liquid chromatography (HILIC) allowed a perfect separation of Histamine from Gentamicin and preservatives. • High resolution Q-TOF mass spectrometry resulted in the best choice to solve a case of Histamine contamination. • A detailed description of method validation and measurement uncertainty evaluation was presented. Abstract Adverse reactions have been reported for antibiotics produced via fermentation with fish peptone due to Histamine contamination. Just few micrograms of Histamine can result in adverse reactions when administered intravenously. Thus in this paper a new method for identification and quantitation of Histamine at ppm levels in the antibiotic Gentamicin is described. The method is based on separation of Histamine from Gentamicin and other excipients present in the drug matrix, by hydrophilic interaction liquid chromatography (HILIC) coupled to a Q-TOF/MS detector; quantitation is based on the standard addition approach. The method was validated for repeatability, inter-day precision, specificity, accuracy (relative and absolute bias) linearity, limit of detection and quantitation. Uncertainty was estimated and evaluated by comparison with values expected according to the Horwitz theory. The method showed satisfactory performances and good sensitivity, reaching a limit of quantitation of approximately 1 ppm. The method proposed can be a starting point for the development of Histamine quantitation methods in other antibiotics or even in other medicinal products which active ingredient is produced via fermentation in presence of fish peptone. [ABSTRACT FROM AUTHOR]

In 2016, USDA-Food Safety and Inspection Service began using a neutralizing buffered peptone water (nBPW) to rinse broiler carcasses for Salmonella and Campylobacter performance standard testing. The nBPW contains standard buffered peptone water (BPW) with compounds to neutralize residual antimicrobials that may be transferred from the carcass to the sample rinsate. However, a direct comparison of nBPW and BPW on carcasses commercially treated with antimicrobials has not been conducted. On 3 replicate days in a commercial broiler processing plant, an immersion chilling biomap using whole carcass rinse samples taken prior to any chilling treatment (30), after pre-chill treatment (30), after primary chill (30), after secondary chill (30), after post-chill treatment (50), and after post-chill treatment without the pre-chill treatment (49) were tested. Carcasses were rinsed with either BPW (without neutralizer) or nBPW. Rinsates were sampled for Salmonella and Campylobacter prevalence and both Enterobacteriaceae (EB) prevalence and counts. No significant differences were observed between sampling sites or rinse media for Salmonella due to an overall low prevalence (4 positive/219 samples). Campylobacter prevalence significantly decreased from prior to chilling (93%) to after all chilling steps (47%) as anticipated (P < 0.0001); however, overall significantly fewer Campylobacter positive carcasses were detected when nBPW was used (55%) in comparison to BPW (70%, P = 0.0258). Both EB prevalence and counts significantly decreased (both P < 0.0001) from prior to chilling (100%, 2.35 log10 CFU/mL) through after all chilling steps (52%, 0.47 log10 CFU/mL). The use of nBPW versus BPW did not impact EB prevalence; however, samples rinsed with nBPW had significantly higher overall counts (1.26 vs. 1.00 log10 CFU/mL, P = 0.0134). The results from this study indicate that the use of a PAA pre-chill treatment did not significantly impact bacteria recovery following all chilling steps. The use of nBPW was effective in neutralizing residual PAA in carcass rinsates when sampling for EB counts; however, nBPW may lessen the ability to detect Campylobacter in these same samples. [ABSTRACT FROM AUTHOR]