The effect of various peptones on the production of cephalosporin C byPaecilomyces persicinus P-10 M1

Summary A microfermentation procedure was employed to determine the effects of peptones on the growth ofPaecilomyces persicinus P-10 M1 and its synthesis of cephalosporin C. Of the peptones tested only papain digest of soy peptone supported the production of cephalosporin C byP. persicinus P-10 M1.     

Growth of Lactobacillus plantarum in media containing hydrolysates of fish viscera

AIMS: To compare growth of Lactobacillus plantarum on media containing hydrolysates (peptones) from cod viscera with growth on commercial media. METHODS AND RESULTS: Growth of Lact. plantarum on various fish peptones and commercial peptones/extracts was evaluated using both a Bioscreen apparatus (microtiter plates, no pH control) and fermentors (with pH control). Generally, the performance of the fish peptones was good and only beaten by the performance of yeast extract. Replacement of the 22 g l(-1) complex nitrogen source in standard MRS medium with only 5 g l(-1) fish peptone reduced the biomass yield with only 10%, whereas replacement with a mixture of 2.5 g l(-1) fish peptone and 2.5 g l(-1) yeast extract increased the biomass yield by 10%. CONCLUSIONS: Peptones derived from cod viscera support excellent growth of Lact. plantarum. SIGNIFICANCE AND IMPACT OF THE STUDY: We show that peptones derived from cod viscera are promising constituents of growth media for fastidious food bacteria such as lactobacilli. Media containing these peptones show excellent performance while problems associated with the use of meat-derived peptones (BSE, kosher status) or plant-derived peptones (genetically modified organisms) are avoided.     

Nitrogen utilization in bacterial isolates from the equine cecum.

A total of 114 bacterial isolates were obtained from the cecal contents of two mature cecally fistulated horses on a habitat-simulating medium containing 40% energy-depleted cecal fluid. Of these isolates, 108 were maintained in pure cultures and were tentatively grouped on the basis of cell morphology and physiological characteristics. Gram-negative rods (50.9%), gram-positive rods (22.8%), and gram-positive cocci (21.9%) represented the largest groups isolated from these animals. Fifty isolates were tested for their ability to grow in media containing urea, ammonia, peptones, or amino acids as sole nitrogen sources. None of the isolates had a unique requirement for urea or ammonia since nitrogen derived from peptones, amino acids, or both supported growth as well as did ammonia or urea in a low nitrogen medium. Of the cecal isolates, 18% were able to use urea for growth, and 20.5% were able to grow with ammonia as the sole nitrogen source. All organisms grew in the experimental media containing peptones as the sole nitrogen source. Urease activity was detected in only 2 of 114 isolates tested. The inability of isolates to use urea or ammonia as nitrogen sources may have been a reflection of growth conditions in the habitat-stimulating medium used for isolation, but it could also suggest that many cecal bacteria require nitrogen sources other then ammonia or urea for growth.     

Nitrogen utilization in bacterial isolates from the equine cecum

A total of 114 bacterial isolates were obtained from the cecal contents of two mature cecally fistulated horses on a habitat-simulating medium containing 40% energy-depleted cecal fluid. Of these isolates, 108 were maintained in pure cultures and were tentatively grouped on the basis of cell morphology and physiological characteristics. Gram-negative rods (50.9%), gram-positive rods (22.8%), and gram-positive cocci (21.9%) represented the largest groups isolated from these animals. Fifty isolates were tested for their ability to grow in media containing urea, ammonia, peptones, or amino acids as sole nitrogen sources. None of the isolates had a unique requirement for urea or ammonia since nitrogen derived from peptones, amino acids, or both supported growth as well as did ammonia or urea in a low nitrogen medium. Of the cecal isolates, 18% were able to use urea for growth, and 20.5% were able to grow with ammonia as the sole nitrogen source. All organisms grew in the experimental media containing peptones as the sole nitrogen source. Urease activity was detected in only 2 of 114 isolates tested. The inability of isolates to use urea or ammonia as nitrogen sources may have been a reflection of growth conditions in the habitat-stimulating medium used for isolation, but it could also suggest that many cecal bacteria require nitrogen sources other then ammonia or urea for growth.     

Evaluation of Nitrogenous Substrates Such as Peptones from Fish:A New Method Based on Gompertz Modeling of Microbial Growth

Fish peptones from tuna, cod, salmon, and unspecified fish were compared with a casein one by using a new method based on Gompertz modeling of microbial growth. Cumulative results obtained from six species of bacteria, yeasts, and fungi showed that, in most cases, these fish peptones are very effective. Nevertheless, this study raised some questions about the standardization of fish raw material, the enzymatic hydrolysis of fish proteins, and the composition of the culture medium used for testing the peptones. Received: 15 June 2000 / Accepted: 17 July 2000     

Evaluation of peptones from chicken waste as a nitrogen source for micro-organisms

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.     

木屑添加对刺芹侧耳菌丝共生细菌多样性和群落结构的影响

细菌作为许多真菌的共生菌,能够有效地促进真菌的代谢生长,而细菌多样性及群落结构能够反映真菌的生长和利用营养物质的状况。本研究利用基于细菌16S rRNA 基因V3-V4区的高通量测序技术分析不同木屑用量对刺芹侧耳菌丝共生细菌群落结构和多样性的影响。结果表明: 5组样品共检测细菌25门52纲114目199科406属,主要的优势菌门为变形菌门(35.0%～85.9%)和厚壁菌门(6.5%～38.4%),优势菌属为不动杆菌属(14.8%～71.6%)和假单胞菌属(1.7%～22.3%)。相较于完全培养基,添加木屑能够提高刺芹侧耳菌丝中的细菌多样性,并使其中优势细菌10个门类、9个属类结构发生显著变化。刺芹侧耳菌丝在5 g木屑培养基上的菌丝生长速度最快,菌丝浓密,边缘整齐,长势优于其他几类培养基;假单胞菌属和乳酸菌属丰度及物种多样性在5 g木屑培养基上都具有一定的优势,且假单胞菌属和乳酸菌属丰度与菌丝长势具有显著的正相关性。木屑作为重要碳源之一,对刺芹侧耳生长发育及其共生细菌群落结构和多样性都有显著影响,这为进一步探索木屑及共生细菌对刺芹侧耳生长发育影响的机理研究奠定了基础。     

Alkalotolerance of Yersinia enterocolitica as a basis for selective isolation from food enrichments.

Alkalotolerance of Yersinia enterocolitica measured in solutions of potassium hydroxide with 0.5% sodium chloride was influenced by the cell suspension medium, temperature, and growth phase. The rate of cell destruction (delta log N per minute) was five times greater at 30 degrees C than at 20 degrees C. Differences in the degree of cell destruction at various concentrations of potassium hydroxide were related to pH and not to osmolarity. The addition of peptones to potassium hydroxide provided a protective effect that was greater for cells suspended in Trypticase soy broth than for those suspended in phosphate-buffered sorbitol-bile salts broth. Log-phase cells were less alkalotolerant than cells in the stationary phase of growth. A modified procedure for alkali treatment, using peptone-supplemented 0.5% potassium hydroxide-0.5% sodium chloride and the addition of a pH 6.6 buffer after treatment to prevent further cell destruction, was used to observe a marked difference in alkalotolerance between Y. enterocolitica and other gram-negative bacteria. Despite this difference, alkali treatment was not highly successful for recovery of Y. enterocolitica from enrichments of seeded foods in comparison with selective enrichment in bile-oxalate-sorbose broth.     

Effect of chitosan on the growth of human colonic bacteria

Growth of 6 bacterial strains representing dominant members of the human colonic microflora was measured in the presence of 0.025, 0.05 and 0.5 % chitosan (from shrimp shells, with a 97 % final degree of deacetylation). The effect of chitosan was variable and dependent on bacterial species. The most susceptible to chitosan were bacteria belonging to genera Bacteroides and Clostridium (91-97% growth inhibition). On the other hand, Roseburia sp., Eubacterium sp. and Faecalibacterium sp. were more resistant (63-83 % inhibition of growth). Chitosan can thus be considered as one of the means for influencing the bacterial population in the human colon.     

Comparison of growth characteristics of anaerobic fungi isolated from ruminant and non-ruminant herbivores during cultivation in a defined medium

Anaerobic fungi were isolated from rumen fluid of a domestic sheep (Ovis aries; a ruminant) and from faeces of five non-ruminants: African elephant (Loxodonta africana), black rhinoceros (Diceros bicornis), Indian rhinoceros (Rhinoceros unicornis), Indian elephant (Elephas maximus) and mara (Dolichotis patagonum). The anaerobic fungus isolated from the sheep was a Neocallimastix species and the isolates from non-ruminants were all species similar to Piromyces spp. A defined medium is described which supported growth of all the isolates, and was used to examine growth characteristics of the different strains. For each fungus the lipid phosphate content was determined after growth on cellobiose and the resulting values were used to estimate fungal biomass after growth on solid substrates. The ability of isolates from ruminants and non-ruminants to digest both wheat straw and cellulose was comparable. More than 90% and 60%, respectively, of filter paper cellulose and wheat straw were digested by most strains within 60-78 h. Growth of two fungi, isolated from rumen fluid of a sheep (Neocallimastix strain N1) and from faeces of an Indian rhinoceros (Piromyces strain R1), on cellobiose was studied in detail. Fungal growth yields on cellobiose were 64.1 g (mol substrate)-1 for N1 and 34.2 g mol-1 for R1. The major fermentation products of both strains were formate, lactate, acetate, ethanol and hydrogen.     

Toxigenic Thermophilic and Thermotolerant Fungi

Twenty-three isolates of fungi, representing 13 thermophilic and thermotolerant species, were bioassayed for toxigenicity to brine shrimp, chicken embryos, and rats. Thirteen isolates representing nine genera were highly toxic to at least two of the three systems. Seven additional isolates of five genera were slightly toxic.     

Lysis of Halobacteria in Bacto-Peptone by Bile Acids

All tested strains of halophilic archaebacteria of the genera Halobacterium, Haloarcula, Haloferax, and Natronobacterium lysed in 1% Bacto-Peptone (Difco) containing 25% NaCl, whereas no lysis was observed with other strains belonging to archaebacteria of the genera Halococcus, Natronococcus, and Sulfolobus, methanogenic bacteria, and moderately halophilic eubacteria. Substances in Bacto-Peptone which caused lysis of halobacteria were purified and identified as taurocholic acid and glycocholic acid. High-performance liquid chromatography analyses of peptones revealed that Bacto-Peptone contained nine different bile acids, with a total content of 9.53 mg/g, whereas much lower amounts were found in Peptone Bacteriological Technical (Difco) and Oxoid Peptone. Different kinds of peptones can be used to distinguish halophilic eubacteria and archaebacteria in mixed cultures from hypersaline environments.     

Autoclavable low cost serum-free cell culture media. The growth of L Cells and BHK cells on peptones

The growth of L-929 cells on a series of peptones, and protein hydrolysates was examined, and it was found that when MEM was supplemented with any of a series of peptones, cell growth was about as good as when serum was used as a supplement. Protein hydrolysates did not support cell growth very well and at higher concentrations actually reduced cell growth. L-929 and L-60TM cells were grown both as monolayers or stationary suspensions and in agitated systems in MEM supplemented with 0.5—1% bactopeptone. The addition of macromolecular compounds, insulin or oleic acid had no effect on cell growth. BHK cells were also grown on media supplemented with bactopeptone but richer media (MEM-alpha, F-12, or RMPI1640) gave higher cell yields. The cells did not form the monolayers observed with fetal calf serum, but a partial suspension system. Addition of a detergent Darvan #2 gave a totally suspension culture in both stationary and agitated systems. The production of Sindbis virus in BHK cells grown in serum-free media was examined and the yield of virus was found to be about the same as that produced in serum-supplemented systems. It is estimated that the cost of cell production media could be reduced by about 90% by the replacement of serum supplement by peptones.     

Occurrence and Activity of Microorganisms in Shrimp Waste

This study aimed to determine the occurrence and respiration activity of heterotrophic bacteria and fungi in shrimp shell waste and to evaluate the role of chitinolytic bacteria and fungi in its decomposition. The highest levels of bacteria were found in shrimp heads sections and the lowest in exoskeletons. The level of fungi was much lower, with the highest proportion present in heads sections and the lowest in exoskeletons. Chitinolytic bacteria constituted a small percentage of the total heterotrophic bacteria in fresh shrimp waste, averaging 4% in exoskeletons, 2.4% in all parts, and 2% in heads. No chitinolytic bacteria were detected in stored waste. In contrast, the percentage of chitinolytic fungi in shrimp waste was much higher than that of bacteria. Chitinolytic fungi constituted 25–60% of the total fungi in fresh waste and 15–40% in stored waste. Chitinolytic bacteria isolated from heads sections were characterized by the highest chitinolytic activity, averaging 11.2 nmol of methylumbelliferyl · mg⁻¹ protein · h⁻¹, whereas the lowest activity was in strains from exoskeletons, averaging 3.2 nmol of methylumbelliferyl · mg⁻¹ protein · h⁻¹. The chitinolytic activity of fungi isolated from all parts waste, head sections, and exoskeletons was similar. The respiration activity of microorganisms in fresh and stored waste was similar. Oxygen consumption activity increased during incubation and approached a saturation value between days 4 and 5. No correlation between the end value of respiratory activity in the analyzed section of shrimp discard after 5 days and the level of bacteria and fungi was observed. The only significant correlation observed was between the respiratory activity of the shrimp and the level of fungi. The respiration activity significantly depended on the analyzed section of shrimp discard (p < 0.000).     

Protein hydrolysates, obtained from crustaceans by an electrochemical method, as a basis for microbiological culture media

The utility of protein hydrolysates extracted electrochemically from crustaceans (Gammarus pulex and shrimp) as major components of microbiological nutrient media was demonstrated. Saprophytic soil bacteria of the genera Bacillus and Pseudomonas and the family Enterobactericeae displayed a good growth and typical morphology of their colonies on the experimental media in question.     

Identification of microorganisms isolated from jet fuel systems

Seventy-two samples from jet aircraft fuel systems were examined for microbial contamination. Ten contaminated samples yielded 43 microorganisms which were classified into nine genera of bacteria and three genera of fungi. The predominant types, comprising about 37% of the isolated cultures, were identified as Bacillus spp. The remaining cultures were distributed among 11 genera, each of which represented 2 to 9% of the total isolates. Four cultures could not be assigned to a genus on the basis of the diagnostic criteria used. Only five isolates, in the genera Pseudomonas and Hormodendrum (Cladosporium), grew abundantly in a mineral salts solution with JP-4 fuel as the sole source of carbon. The presence of fuel utilizers in a fuel system may be a better index to potential problems that have been correlated with microbial contamination than the presence of aerobic sporeforming bacilli.     

The growth of L-cells and Vero cells on an autoclavable MEM-peptone medium.

The growth of L-60TM cells (a suspension culture adapted L-cell) on media composed of MEM (minimum essential medium (Eagle)) and bactopeptone autoclaved together or separately under a variety of conditions has veen determined. It has been found that MEM autoclaved with 0.5% bactopeptone at 15 psi for 20 min, cooled and then neutralized with NaHCO3, consistently supported good cell growth of L-60TM and L-929 cells. Similar results were obtained when the MEM and bactopeptone were autoclaved separately. The cells grew initially as a monolayer, subsequently becoming a stationary suspension. Some experiments were carried out with agitated suspension culture of L-60TM cells in the autoclaved MEM-bactopeptone combination with and without added methylcellulose and results were obtained which indicate that large scale suspension culture is possible in this system. Other peptones were also found to support cell growth. The autoclaved MEM-bactopeptone combination also supported the growth of Chang liver and Vero cells. The Chang liver cells rapidly dissociated from the plastic surface but the Vero cells remained sufficiently securely attached so that it was possible to grow them near to confluency in roller bottles.     

Crude peptones from cowtail ray (Trygon sephen) viscera as microbial growth media

In the processing of cowtail ray (Trygon sephen) in Indonesia, viscera (up to 20% body weight) is wasted together with the head, frame and skin. A series of studies have been carried out to investigate the utilization of the viscera, and the present paper reports the conversion of the viscera into microbiological peptones. Ensilation using 3% (v/w) mixture of propionic and formic acids (1:1, v/v), followed by vacuum evaporation, has been used to prepare crude liquid peptones from cowtail ray viscera. These peptones were compared to three commercial peptones in supporting the growth of microorganisms. Mixed populations of microorganisms from foods (beef, egg and milk) and selected pure microorganisms (Aspergillus flavus, Bacillus subtilis, Saccharomyces cerevisiae, Escherichia coli and Staphylococcus aureus) were grown on liquid media containing 0.5 g test peptones/100 ml and the optical densities were monitored. The biomass produced was measured at the end of incubation period. The results show that crude peptones from cowtail ray viscera performed similar to or even better than commercial peptones as nitrogen sources for microorganisms growth. This revised version was published online in July 2006 with corrections to the Cover Date.     

温室黄瓜叶部微生物区系

采用稀释分离法和消毒叶片研磨液培养法对温室黄瓜叶围和内生微生物进行了分离,共分离到248个菌株,初步鉴定出13个属的叶围真菌,其中链格孢属(Alternaria)和青霉属(Penicillium)真菌为优势类群;鉴定出4个属的内生真菌,其中曲霉属(Aspergillus)真菌为优势类群;10个属的叶围细菌,其中芽孢杆菌属(Bacillus)和黄单胞菌属(Xanthomonas)细菌为优势类群;6个属的内生细菌,其中芽孢杆菌属和假单胞菌属(Pseudomonas)细菌为优势类群;6个属的叶围酵母菌,其中隐球酵母属(Cryptococcus)为优势类群;已鉴定出2个属的叶围放线菌,分别为链霉菌属(Streptomyces)和小多孢菌属(Micropolpspora).未分离到内生酵母菌和放线菌.     

Hydrophobic peptide auxotrophy in Salmonella typhimurium.

The growth of a pleiotropic membrane mutant of Salmonella typhimurium with modified lipopolysaccharide composition was found to be strictly dependent on the peptone component of complex media. Nutritional Shiftdown into minimal media allowed growth for three to four generations. Of 20 commercial peptones, only enzymatic digests supported growth to varying degrees. Neither trace cations, amino acids, vitamins, carbohydrates, lipids, glutathione, polyamines, carbodimides, nor synthetic peptides stimulated growth; however, cells still metabolized carbohydrates, and amino acid transport systems were shown to be functional. A tryptic digest of casein was fractionated into four electrophoretically different peptide fractions of 1,000 to 1,200 molecular weight which supported growth to varying degrees. The best of these was further fractionated to two highly hydrophopic peptides. N-terminal modifications eliminated biological activity. Fluorescein-conjugated goat antibody to rabbit immunoglobulin G was used as a probe to detect antipeptide antibody-peptide complexes on membrane preparations. Cells grown on peptone distributed the peptide into both inner and outer membranes. The peptide could be removed with chaotropic agents, and cells had to be pregrown in peptone-containing media to bind the hydrophobic peptide. The gene (hyp) responsible for peptide auxotrophy was mapped at 44 to 45 units by conjugation.