Studies on Choanephoraceae. IV. Carbon requirements

Summary The comparative utilization of different carbon compounds byBlakeslea trispora, Choanephora cucurbitarum, Choanephora infundibulifera, Choanephora conjuncta, Choanephora heterospora andChoanephora circinans was studied under controlled conditions. Of the monosaccharides, rhamnose and sorbose were poorly utilized, while the rest of them were favourably utilized by all the species. Amongst the disaccharides, maltose proved to be the best. Sucrose, lactose and melibiose were poor sources. Raffinose, the only trisaccharide used supported poor growth of all the species. Of the polysaccharides used, starch and glycogen supported good growth of all the species. Dextrin and inulin were used in varying degrees by the present species. Both sorbitol and mannitol supported growth of the fungi in varying degrees. All the organic acids used, proved to be valueless in the present investigation.In some cases good sporulation was accompanied with good or moderate growth. No correlation with regard to the growth and sporulation could be established. The final pH of media showed a tendency to drift towards the alkaline side in most of the cases.     

Effect of carbon source on growth,nitrogenase and uptake hydrogenase activities of Frankia isolates from Casuarina sp.

The effect of different carbon sources on the growth of Frankia isolates for Casuarina sp. was studied. In addition, regulation of nitrogenase and uptake hydrogenase activity by carbon sources was investigated. For each of the three isolates, JCT287, KB5 and HFPCcI3, growth was greatest on the carbon sources pyruvate and propionate. In general the carbon sources which gave the greatest growth gave the highest levels of nitrogenase activity, but repressed the activity of uptake hydrogenase. The regulation of growth, uptake hydrogenase activity and nitrogenase activity is discussed.     

Metabolic Characterization of cold active Pseudomonas, Arthrobacter, Bacillus, and Flavobacterium spp. from Western Himalayas

Himalayan soils undergo dramatic temporal changes in their microclimatic properties. The soil habitats in the high altitude cold habitats of Himalayas are little explored with respect to bacterial diversity and metabolic potentials of the bacterial species. Soil habitat in Western Himalayas is dominated by the genera of Pseudomonas, Arthrobacter, Bacillus, and Flavobacterium. Strains were found to be diverse in their metabolic potentials to utilize different carbon sources by growing them on media containing 114 different sole carbon sources. Bacillus sp. STL9 was supported by the lowest number (12.3%) of the carbon sources while growth was observed in 73.7% of the carbon sources tested for the Pseudomonas sp. SPS2. Carbohydrates appeared to be preferred carbon sources for these Himalayan isolates followed by amino acids and proteins. These microbes also produced various extra-cellular hydrolytic enzymes having biotechnological potentials, lipase being the one secreted by most strains (85.7%) followed by β-galactosidase (42.8%). Antibiotic resistance profiling for 85 different antibiotics has also been described.     

An optimum environment for the culturing of cytospora isolates from stone fruits. II. Carbon sources

Summary Six isolates (Cytospora cincta Fr. andC. leucostoma Fr.) were innoculated to liquid and solid synthetic laboratory media containing nine different sources of carbon.One of the isolates did not grow. The remaining five grew at rates, and in relationships, which segregated them in accordance with their species grouping. These relationships were more nearly constant than any other relationships previously noted in Idaho for these or otherCytopora isolates.Two conclusions were reached: 1) For best growth and sporulation, maltose should be incorporated in the laboratory culture medium and not the commonly used dextrose, which was demonstrated to be an inferior source of carbon; and 2) separate investigations, which utilize different carbon sources in the laboratory media, are likely to yield sufficiently different results that co-identity of species strains used by the separate workers may not be evident.Approved by the Director of the Idaho Agricultural Experiment Station as Research Paper No. 489.     

CULTURE AND HETEROTROPHY OF THE FRESHWATER DINOFLAGELLATE,PERIDINIUM CINCTUM FA. OVOPLANUM LINDEMAN1

A defined minimal medium was developed for an axenic strain of Peridinium (Indiana Culture No. LB 1336). Thiamine, biotin, and vitamin B₁₂ did not stimulate growth. Of 15 organic carbon sources tried in light, fructose, galactose, glucose, malate, malonate, and pyruvate enhanced growth but propionate retarded growth. In dark-grown cultures only media with succinate permitted growth above the survival level. Stimulation of growth by organic carbon sources was markedly pH dependent.     

GROWTH OF PHELLINUS (PORIA) WEIRII ON DIFFERENT VITAMINS AND CARBON AND NITROGEN SOURCES

Mycelial growth of Phellinus weirii (Murr.) Gilb., a root pathogen of conifers in the Pacific Northwest, was studied in defined liquid media with different carbon and nitrogen sources and vitamins. The fungus grew significantly more on glucose, xylose, maltose, or fructose than on other carbon sources. Starch did not support growth. Maximum growth occurred in 4 weeks on all carbon sources except dextrin and sucrose, with which maximum growth occurred in 3 weeks. Of the nitrogen sources, peptone supported the best growth of the fungus; glutamic acid, serine, aspartic acid, alanine, leucine, ammonium sulphate, and urea supported significantly better growth than tyrosine, arginine, methionine, threonine, and glycine. Potassium nitrate, phenylalanine, sodium nitrate, lysine, proline, and cysteine inhibited growth. Thiamine hydrochloride was not absolutely required for growth of P. weirii, but better growth was obtained with its addition. The fungus showed no significant responses to a range of other vitamins.     

Effects of Carbon Source, Carbon Concentration, and Chlorination on Growth Related Parameters of Heterotrophic Biofilm Bacteria

Abstract To investigate growth of heterotrophic biofilm bacteria, a model biofilm reactor was developed to simulate a drinking water distribution system. Controlled addition of three different carbon sources (amino acids, carbohydrates, and humics) at three different concentrations (500, 1,000, and 2,000 ppb carbon) in the presence and absence of chlorine were used in separate experiments. An additional experiment was run with a 1:1:2 mixture of the above carbon sources. Biofilm and effluent total and culturable cells in addition to total and dissolved organic carbon were measured in order to estimate specific growth rates (SGRs), observed yields, population densities, and bacterial carbon production rates. Bacterial carbon production rates (μg C/L day) were extremely high in the control biofilm communities (range = 295–1,738). Both growth rate and yield decreased with increasing carbon concentrations. Therefore, biofilm growth rates were zero-order with respect to the carbon concentrations used in these experiments. There was no correlation between growth rate and carbon concentration, but there was a significant negative correlation between growth rate and biofilm cell density (r=−0.637, p= 0.001 control and r=−0.57, p= 0.021 chlorinated biofilms). Growth efficiency was highest at the lowest carbon concentration (range = 12–4.5%, amino acids and humics respectively). Doubling times ranged from 2.3–15.4 days in the control biofilms and 1–12.3 days in the chlorinated biofilms. Growth rates were significantly higher in the presence of chlorine for the carbohydrates, humics, and mixed carbon sources (p= 0.004, < 0.0005, 0.013, respectively). The concept of r/K selection theory was used to explain the results with respect to specific growth rates and yields. Humic removal by the biofilm bacteria (78% and 56% for the control and chlorinated biofilms, respectively) was higher than previously reported literature values for planktonic bacteria. A number of control experiments indicated that filtration of drinking water was as effective as chlorination in controlling bacterial biofilm growth. Received: 26 March 1999; Accepted: 3 August 1999; Online Publication: 15 February 2000     

不同碳源和生长因子条件下粒毛盘菌代谢产物初步研究

采用GC-MS法对一种粒毛盘菌(Lachnum sp.)在不同碳源、生长因子条件下发酵代谢产物的挥发性成分组成与差异进行分析。结果显示,不同碳源和生长因子条件下产生的代谢产物不同,主要包括有机酸、胺类、烷烃类、酯类、醇类、吡咯等物质。分别以20 g/L的葡萄糖、蔗糖、淀粉为碳源的发酵液中检测到的挥发性代谢产物为7、7、10种;添加1 mg/L的V_C、V_(B1)、甘氨酸、色氨酸作为不同生长因子的发酵液中检测到的挥发性代谢产物分别为6、7、7、12种。结果显示粒毛盘菌YM406发酵代谢产物具有丰富的多样性,并且在不同的培养条件下产生的代谢产物存在一定的差异。     

The FRP1 F-box gene has different functions in sexuality, pathogenicity and metabolism in three fungal pathogens

Plant‐pathogenic fungi employ a variety of infection strategies; as a result, fungi probably rely on different sets of proteins for successful infection. The F‐box protein Frp1, only present in filamentous fungi belonging to the Sordariomycetes, Leotiomycetes and Dothideomycetes, is required for nonsugar carbon catabolism and pathogenicity in the root‐infecting fungus Fusarium oxysporum. To assess the role of Frp1 in other plant‐pathogenic fungi, FRP1 deletion mutants were generated in Fusarium graminearum and Botrytis cinerea, and their phenotypes were analysed. Deletion of FgFRP1 in F. graminearum led to impaired infection of barley roots, but not of aerial plant parts. Deletion of BcFRP1 in B. cinerea did not show any effect on pathogenicity. Sexual reproduction, however, was impaired in both F. graminearum and B. cinerea FRP1 deletion mutants. The mutants of all three fungi displayed different phenotypes when grown on an array of carbon sources. The F. oxysporum and B. cinerea deletion mutants showed opposite growth phenotypes on sugar and nonsugar carbon sources. Replacement of FoFRP1 in F. oxysporum with the B. cinerea BcFRP1 resulted in the restoration of pathogenicity, but also in a switch from impaired growth on nonsugar carbon sources to impaired growth on sugar carbon sources. This effect could be ascribed in part to the B. cinerea BcFRP1 promoter sequence. In conclusion, the function of the F‐box protein Frp1, despite its high sequence conservation, is not conserved between different fungi, leading to differential requirements for pathogenicity and carbon source utilization.     

Modeling of growth kinetics for an isolated marine bacterium,Oceanimonas sp. BPMS22 during the production of a trypsin inhibitor

Abstract

Protease inhibitors significantly control physiologically relevant protease activities. Protease inhibitors from marine microbial sources are unique due to their rough living environmental conditions. In the present study, a protein protease inhibitor (PI) was produced from marine Oceanimonas sp. BPMS22. Seven different media were screened for the growth of the bacterium and production of PI. Different carbon and nitrogen sources were screened and optimized for the specific protease inhibitor activity. Three different growth models were checked for the best fit of the bacterial growth. A modified Gompertz model was selected as the best model for the growth of Oceanimonas sp. BPMS22 with the maximum specific growth rate of 0.165?hr^?1 and doubling time of 4.2?hr. The production of PI takes place during the non-growing phase of the bacterial growth. A kinetic model for the production of PI during non-growing phase was used for studying various process parameters. From the model, the maximum trypsin inhibitor formation rate of 0.3802?IU per mg of biomass per hour was observed at 49.91?hr.     

Accumulation of polyhydroxyalkanoates by Microlunatus phosphovorus under various growth conditions

Microlunatus phosphovorus is an activated-sludge bacterium with high levels of phosphorus-accumulating activity and phosphate uptake and release activities. Thus, it is an interesting model organism to study biological phosphorus removal. However, there are no studies demonstrating the polyhydroxyalkanoate (PHA) storage capability of M. phosphovorus, which is surprising for a polyphosphate-accumulating organism. This study investigates in detail the PHA storage behavior of M. phosphovorus under different growth conditions and using different carbon sources. Pure culture studies in batch-growth systems were conducted in shake-flasks and in a bioreactor, using chemically defined growth media with glucose as the sole carbon source. A batch-growth system with anaerobic–aerobic cycles and varying concentrations of glucose or acetate as the sole carbon source, similar to enhanced biological phosphorus removal processes, was also employed. The results of this study demonstrate for the first time that M. phosphovorus produces significant amounts of PHAs under various growth conditions and with different carbon sources. When the PHA productions of all cultivations were compared, poly(3-hydroxybutyrate) (PHB), the major PHA polymer, was produced at about 20–30% of the cellular dry weight. The highest PHB production was observed as 1,421 mg/l in batch-growth systems with anaerobic–aerobic cycles and at 4 g/l initial glucose concentration. In light of these key results regarding the growth physiology and PHA-production capability of M. phosphovorus, it can be concluded that this organism could be a good candidate for microbial PHA production because of its advantages of easy growth, high biomass and PHB yield on substrate and no significant production of fermentative byproducts.     

Impact of carbon sources on growth and oxalate synthesis by the phytopathogenic fungus <Emphasis Type="Italic">Sclerotinia sclerotiorum</Emphasis>

The impact of various supplemental carbon sources (oxalate, glyoxylate, glycolate, pyruvate, formate, malate, acetate, and succinate) on growth and oxalate formation (i.e., oxalogenesis) by Sclerotinia sclerotiorum was studied. With isolates D-E7, 105, W-B10, and Arg-L of S. sclerotiorum, growth in an undefined broth medium (0.1% soytone; pH 5) with 25 mM glucose and 25 mM supplemental carbon source was increased by the addition of malate and succinate. Oxalate accumulation occurred in the presence of glucose and a supplemental carbon source, with malate, acetate, and succinate supporting the most oxalate synthesis. With S. sclerotiorum Arg-L, oxalate-to-biomass ratios, an indicator of oxalogenic potential, were dissimilar when the organism was grown in the presence of different carbon sources. The highest oxalate-to-biomass ratios were observed with pyruvate, formate, malate, acetate, and succinate. Time-course studies with acetate-supplemented cultures revealed that acetate and glucose consumption by S. sclerotiorum D-E7 coincided with oxalogenesis and culture acidification. By day 5 of incubation, oxalogenesis was halted when cultures reached a pH of 3 and were devoid of acetate. In succinate-supplemented cultures, oxalogenesis essentially paralleled glucose and succinate utilization over the 9-day incubation period; during this time period, culture pH declined but never fell below 4. Overall, these results indicate that carbon sources can regulate the accumulation of oxalate, a key pathogenicity determinant for S. sclerotiorum.     

Polyhydroxybutyrate in <Emphasis Type="Italic">Rhizobium</Emphasis> and <Emphasis Type="Italic">Bradyrhizobium</Emphasis>: quantification and <Emphasis Type="Italic">phbC</Emphasis> gene expression

Polyhydroxyalkanoates (PHAs) are hydroxyalkanoate polymers that are produced and accumulate by many kinds of bacteria. These polymers act as an energy store for bacteria. Polyhydroxybutyrate (PHB) is the most studied polymer in the PHA family. These polymers have awakened interest in the environmental and industrial research areas because they are biodegradable and have thermoplastic qualities, like polypropylene. In this work, we analyzed the PHB production in Bradyrhizobium sp., Rhizobium leguminosarum bv. phaseoli, and Rhizobium huautlense cultured with two different carbon sources. We did biochemical quantification of PHB production during the three phases of growth. Moreover, these samples were used for RNA extraction and phbC gene expression analysis via real-time PCR. The bacteria showed different manner of growth, PHB accumulation and phbC gene expression when different quantity and quality of carbon sources were used. These results showed that under different growth media conditions, the growth and metabolism of different species of bacteria were influenced. These differences reflect the increase or decrease in PHB accumulation.     

Biosynthesis of extracellular low-molecular-mass papain and trypsin inhibitors by Streptomyces sp. 22: effect of cultural conditions

The production of extracellular inhibitors of papain and trypsin by Streptomyces sp. 22 was studied under different cultural conditions including complex and defined media, temperatures ranging from 18 °C to 37 °C and a variety of sole carbon and nitrogen sources. In complex nutritionally rich medium, maximal specific growth rates were obtained at 37 °C, whereas the highest specific production rates for both papain and trypsin inhibitors were registered at 18 °C. Studies on the effect of different carbon and nitrogen sources in defined media underline the importance of the nitrogen source as a strong regulator of the biosynthesis of both inhibitors. Enhanced formation of the inhibitory compounds occurred in the presence of casein. The dynamics of the formation of both inhibitors in defined media showed close association with growth. However, a partial separation of production phases for papain and trypsin inhibitors was observed in complex medium. The results imply differences in the regulation of biosynthesis of the two inhibitors.     

Polymer production by a mucoid stain of Azotobacter vinelandii in batch culture

Summary Influence of laboratory growth conditions and soil conditions on the survival of Pseudomonas fluorescens R1, a spontaneous rifamycin-resistant mutant of P. fluorescens W1, in soil was investigated. Strain R1 is antagonistic to Gaeumannomyces graminis and Rhizoctonia solani in vitro. Characteristics of W1 are scarcely different from those of R1 with respect to growth rates, plasmids, and the ability to use 56 substrates as carbon sources. Growth conditions varied were: medium composition, pH, temperature, carbon source, and nitrogen source. Strain R1 was released into a laboratory model ecosystem and soil conditions were varied with respect to sterility, texture, moisture content, temperature, and addition of carbon and nitrogen sources. The effect of initial population density of R1 on survival in soil was also investigated. The survival of R1 in soil was influenced only to a small extent by different growth conditions; soil conditions were of greater importance. However, no conditions could be found to maintain more than 0.7% of the initial number of cells in soil. No positive rhizosphere effect in glasshouse experiments was observed. Bacterization of wheat seeds with suspensions of R1 led to an increase in cells on developing roots. A further Pseudomonas strain, P. fluorescens W2, isolated from wheat roots, showed the same survival characteristics as R1.     

Descriptive Physiology and Biochemistry of the Abnormally Ripening Tomato Fruit (Lycopersicon esculentum) cv. Snowball

Aspergillus tamarii Kita grew and sporulated best at 30°C. The best pH for growth and sporulation were 5.5 and 6.5, respectively. Among the carbon sources employed, glucose supported the highest growth and sporulation. Best growth was obtained with sodium nitrate as nitrogen source and best sporulation with ammonium tar-tarate. When glucose was used as carbon source, the carbohydrates found in the mycelium included myoinositol. dulcitol, fructose, arabinose and ribose.     

Effect of different carbon and nitrogen sources on the growth and sporulation of Claviceps microcephal (Wallr) TUL.

The effect of different carbon and nitrogen compounds on growth and sporulation ofC. microcephala (Wallr.)Tul. causing ergot disease of Bajra has been studied. Nine different sources of carbon were used but cane sugar was found to be the best source for both, growth and sportulation of the fungus. Glucose, sucrose and maltose gave good growth but fair sporulation. Lactose and sorbitaol proved to be the poor sources. However, fungus failed to utilize starch, dextrin and mannitol.Nineteen nitrogen compounds were tried for the growth and sporulation of the fungus. Best growth and sporulation were supported by peptone and glycine. L-asparagine, DL-valine, Urea, magnesium nitrate and L-proline supported good growth and fair sporulation except DL-valine where it was excellent. Poor growth was obtained on L-isoleucin, ammonium sulphate, potassium nitrate,-alanine, ammonium chloride, DL-aspartic acid and DL-methionine. Fungus failed to utilize thio-urea.     

Determination of optimal carbon source and pH value for sclerotial formation of Polyporus umbellatus under artificial conditions

Polyporus umbellatus is one of the precious medicinal fungi, with sclerotia used as a diuretic agent and antidote in China for many years. This has led to the present interest in producing sclerotia of P. umbellatus in the laboratory due to a decreased abundance in natural sources. Here, we investigated the determining factors for sclerotial formation in P. umbellatus. Five carbon sources, namely, maltose, fructose, glucose, sucrose and soluble starch with different initial pH values were evaluated for their effects on mycelial growth and sclerotial development of P. umbellatus. Maltose, fructose and glucose could induce sclerotial formation of P. umbellatus. Sucrose and soluble starch could stimulate growth of the fungus but had no effect on sclerotial formation. The most efficient sclerotial production occurred with maltose followed by fructose and a pH of 5. In addition, different macroscopically evident characteristics of sclerotial development of P. umbellatus induced by different carbon sources were also observed. Our findings could provide new insights into further research on sclerotial production in P. umbellatus under artificial cultivation.     

Physiological and biochemical contributions to the taxonomy of the genus Prototheca

Prototheca zopfii (12 strains) is able to use glucose, fructose, propanol, glycerol, and acetate as sources of carbon for growth. One of the strains is biochemically (utilization also of galactose and mannose), and two strains are morphologically slightly different.Two strains can be identified as P. wikerhamii. They exhibit good growth with glucose, fructose, galactose, trehalose, propanol, glycerol, acetate, and glutamate as sources of carbon. P. spec. 263-2 grows only with glucose and acatate. P. zopfii and P. wickerhamii are able to use urea, glycine, and glutamate as sources of nitrogen. P. spec. 263-2, on the other hand, cannot utilize these organic nitrogen compounds for growth.Four strains of Chlorella protothecoides are able to use glucose, fructose, galactose, and acetate as sources of carbon for growth in the dark. Three of them utilize also mannose, trehalose, and glutamate. Two strains can grow with glycerol, and one is able to use lactose. — Urea and glycine can serve as sources of nitrogen for the four strains of C. protothecoides. Glutamate supports growth of three strains, and one strain is able to use nicotinamide.     

Studies on the nutrition of Arthrobotrys oligospora Fres. and A. robusta Dudd: The saprophytic phase

Growth requirements of two predaceous hyphomycetes in the absence of eelworm prey were determined in specified culture media, in an investigation of the interrelationship of eelworm and fungi. Both fungi were able to utilize a wide range of energy sources and gave the highest yields of mycelium when the carbon sources supplied had the same configuration as glucose around carbon atoms, 3, 4, 5 and 6, or were oligosaccharides yielding glucose on hydrolysis. The species differed in their ability to utilize nitrogen sources, A. robusta producing very little growth when nitrate was the sole source of nitrogen, and comparatively little on aspartate nitrogen. Both responded to thiamin, biotin and p-aminobenzoic acid, but neither species showed absolute dependence on an external source of vitamin.