Showing papers on "Bacteria published in 1976"
517 citations
TL;DR: Surface-sterilized ovules and seeds of 27 species of plants were cultured in the water of syneresis of a nutrient medium low in agar content and only one species of bacteria was recovered in 93% of the instances in which bacteria were obtained.
Abstract: Surface-sterilized ovules and seeds of 27 species of plants were cultured in the water of syneresis of a nutrient medium low in agar content. Bacteria were obtained from 30% of the ovules, 15% of the seeds of herbaceous plants, 16% of the seeds of woody plants, 5.4% of the overwintered noncereal seeds, and 13.5% of overwintered cereal seeds. In no instance did every ovule or seed of a plant species contain bacteria. No bacteria were obtained from the hard, waxy seeds of mimosa or yellowwood. They were not obtained from ovules with unbroken coats or from seeds with coats that were not ruptured during the swelling of the seed. Only one species of bacteria was recovered in 93% of the instances in which bacteria were obtained. Bacteria were obtained from seeds that were embedded in the acidic parenchyma of the lemon or surrounded by the thickened flesh of the cucurbits. The bacteria were distributed among 19 genera and 46 species. The species isolated in greatest numbers were Bacillus megaterium, B. cereus, Erwinia herbicola, Flavobacterium devorans, and Pseudomonas fluorescens. Bacteria recovered less frequently were in the genera Achromobacter, Acinetobacter, Alcaligenes, Brevibacterium, Corynebacterium, Cytophaga, Leuconostoc, Micrococcus, Nocardia, Proteus, Streptococcus, Streptomyces, and Xanthomonas. Members of 11 genera and 15 species of bacteria were isolated once.
230 citations
TL;DR: Culture supernatant fluids of 50 phosphate-dissolving bacteria isolated from rhizospheres of crop plants were examined for IAA, gibberellins and cytokinins and plant growth inhibitors were detected in cultures of some isolates.
Abstract: Culture supernatant fluids of 50 phosphate-dissolving bacteria isolated from rhizospheres of crop plants were examined for IAA, gibberellins and cytokinins. These bacteria possessed phytase activity and 27 could dissolve rock phosphate. Twenty bacteria synthesized all 3 types of plant hormones, 43 produced IAA, 29 formed gibberellins and 45 cultures produced cytokinin-like substances. Of the 50 bacteria tested 28 decomposed IAA. Plant growth inhibitors were detected in cultures of some isolates. The ecological significance of these rhizosphere bacteria and their mode of action when used as inoculants is considered.
213 citations
TL;DR: This bacterium differs from all previously described genera and species of methane-oxidizing bacteria in its ability to utilize a variety of organic substrates with carbon-carbon bonds as sources of carbon and energy.
Abstract: A new genus and a new species of methane-oxidizing bacteria are described. The colonies produced by these bacteria are pink, circular, and convex with entire margins. Cells are gram negative and are normally found singularly with some rosettes. Negative stains indicate polar flagellation. In thin sections, intracytoplasmic membranes, similar to those described as type II in other methylotrophs, were present when the cells were grown with methane. No such membranes were apparent when the cells were grown with the other carbon and energy sources tested. The serine pathway for formaldehyde incorporation is the pathway of C1 metabolism. The deoxyribonucleic acid base composition is 66 mol% guanine plus cytosine. Methylobacterium is proposed as the name for this new genus of rod-shaped, methane-oxidizing bacteria. The specific epithet in the name of the type species, Methylobacterium organophilum sp. nov., denotes the preference of this organism for organic carbon and energy sources more complex than methane. The type strain of M. organophilum is XX (= ATCC 27886). This bacterium differs from all previously described genera and species of methane-oxidizing bacteria in its ability to utilize a variety of organic substrates with carbon-carbon bonds as sources of carbon and energy. The pathways for methane oxidation and the assimilation of one-carbon units are repressed during growth on complex organic substrates.
211 citations
TL;DR: A medium is described which was designed for use in testing the minimal inhibitory concentration of antibiotics for anaerobic bacteria by agar dilution and does not require the addition of blood to support growth of most clinical isolates of an aerobic bacteria.
Abstract: A medium is described which was designed for use in testing the minimal inhibitory concentration of antibiotics for anaerobic bacteria by agar dilution. It contains: Trypticase (1%), Gelysate (1%), yeast extract (0.5%), glucose (0.1%), pyruvate (0.1%), arginine (0.1%), NaCl (0.5%), hemin (5 μg/ml), vitamin K1 (0.5 μg/ml), agar (1.5%). The medium does not require the addition of blood to support growth of most clinical isolates of anaerobic bacteria.
197 citations
197 citations
TL;DR: Data indicate that persistence of a positive culture may be related to large initial concentrations of bacteria, and are consistent with the hypothesis that lactic acid dehydrogenase activity in cerebrospinal fluid is derived from bacteria.
196 citations
TL;DR: It is proposed that bacterial and eukaryotic oxygen respiration arose from the dual-function Photosynthetic and respiratory electron chain in purple non-sulfur bacteria, by the loss of photosynthetic capabilities.
192 citations
TL;DR: It is concluded from the results that the fraction of very small heterotrophic bacteria which cannot be cultured on nutrient media is responsible for the continuous breakdown of organic matter in off-shore regions of the sea.
Abstract: Substrate transformation and microbial biomass production in aquatic ecosystems depend mainly on the total number of actively metabolizing heterotrophic bacteria. The most common methods used concern the determination of either the colony-forming bacteria or the total number of bacteria including autotrophs and inactive organisms a micro-autoradiographic method is presented which enables the substrate uptake of single bacteria by means of 3H-amino-acid mixture and Nuclepore filters to be determined. The standardization procedure revealed the greatest success after 3 h incubation with 10 μCi/ml tritiated amino-acid mixture and an exposure of 14 days to the X-ray film. Preliminary experiments showed inactivation of an active fresh-water population from 100% to 0.6% within 3 h at 28‰S. With increasing distance from the shore, the number of colony-forming units decreases from 6 to 0.01% of the total number of active heterotrophic bacteria. It is concluded from the results that the fraction of very small heterotrophic bacteria which cannot be cultured on nutrient media is responsible for the continuous breakdown of organic matter in off-shore regions of the sea.
189 citations
TL;DR: Ten different compounds have been partially purified and characterized and show a different degree of specificity as growth inhibitors of a series of enterobacteria as well as other non-enteric microorganisms.
165 citations
TL;DR: Interactions between vesicular-arbuscular mycorrhizal fungi and phosphate-solubilizing bacteria were studied in a low-phosphate alkaline soil amended with 0, 0.1% and 0.5% rock phosphate to find plants not inoculated with bacteria or Endogone derived no benefit from the rock phosphate.
Abstract: Interactions between vesicular-arbuscular (VA) mycorrhizal fungi and phosphate-solubilizing bacteria were studied in a low-phosphate alkaline soil amended with 0, 0.1% and 0.5% rock phosphate. Endogone (E3 and yellow vacuolate spore types) and two bacteria able to solubilize rock phosphate in vitro and produce plant growth regulating substances were used as inocula. Lavender ( Lavandula spica var. vera L.) plants with mycorrhiza plus bacteria (either E3 plus bacteria or “yellow vacuolate” plus bacteria treatments) took up more total P than plants with either Endogone or bacteria separately at each concentration of rock phosphate. Plants not inoculated with bacteria or Endogone derived no benefit from the rock phosphate.
TL;DR: Microbial fractions, comprising protozoa, large and small bacteria and whole particulate matter, have been isolated from rumen contents of sheep given a mainly concentrate diet, a mixture of hay and concentrate, and hay only.
Abstract: Microbial fractions, comprising protozoa, large and small bacteria and whole particulate matter, have been isolated from rumen contents of sheep given a mainly concentrate diet, a mixture of hay and concentrate, and hay only. Samples of rumen contents were taken before and 2 h after feeding. The main components determined were: protein, lipid, nucleic acids, carbohydrate and ash. The amount of cell wall was estimated in terms of known cell wall constituents (diaminopimelic acid (DAP) and glucosamine). The concentration of some of the constituents varied with diet and with respect to the time of feeding. Many of the differences disappeared when the results were expressed on a polysaccharide-free basis. The amino acid composition of large and small bacteria was virtually the same. The amino acid composition of protozoa was similar except for the proportions of glutamic acid and lysine which were greater in protozoa, and alanine, glycine and DAP, the proportions of which were greater in bacteria. There were higher proportions of protein in large bacteria and protozoa than in small bacteria. Small bacteria contained more lipid, ash and DNA, and less RNA than the other two fractions. The polysaccharide content of protozoa and large bacteria increased from about 8% before feeding to about 30% after feeding, while the polysaccharide content of small bacteria increased only slightly after feeding.
TL;DR: In this article, the authors examined the effect of environmental factors on the attachment of rumen bacteria to starch and found that corn starch was better both in the amount of bacteria attached per unit weight of starch and in ease of handling than other starches from different origin as adsorbent for bacterial attachment.
Abstract: Corn starch was better both in the amount of bacteria attached per unit weight of starch and in easiness of handling than other starches from different origin as adsorbent for bacterial attachment. The attachment of bacteria to starch occurred shortly after the addition of starch granules, and a maximum attachment was attained after further 5-min incubation at 38°. The amount of bacteria attached to starch granules was approximately proportional to the quantity of granules added until 2.5% in weight per volume. Effect of environmental factors on the attachment of rumen bacteria to starch was examined. The attachment of bacteria to starch was maximal in a medium containing sodium carbonate above 0.15%. Carbon dioxide as gas phase was far better in the attachment of bacteria to starch than hydrogen and nitrogen gases. There existed bacteria capable of attaching to starch even at 4° or for the first time at above 30°. The amount of bacteria attached to starch was small at 4° and more abundant at 38°.A trial was made to elute bacteria attached to starch granules first with a salt solution and subsequently with Formalin. The results obtained showed that bacteria attached to starch, excepting those attached at 4°, included the following three types of bacteria. The bacteria of thefirst type were those loosely attaching to starch, that were eluted easily with a salt solution. The bacteria of the second type were those firmly attached and were eluted for the first time with Formalin. The bacteria of the third type were those with irreversibly attaching ability, that were not eluted even with Formalin.The most characteristic properties of bacteria attached to starch were their amylase and urease activities. The specific amylase activity of bacteria attached to starch was remarkably high, compared with that of non-attached bacteria. There was little or no specific urease activity of attached bacteria, while that of non-attached bacteria was relatively high. There was no significant difference in the specific activity of other four hyrolases between bacteria attached and non-attached to starch.The actual role of bacteria which are apt to attach to starch in the rumen in situ is also discussed.
TL;DR: Ch Chromosomal deoxyribonucleic acid thus determines specificity of this essential component of the Agrobacterium infection process.
Abstract: Lipopolysaccharide (LPS) isolated from Agrobacterium tumefaciens inhibited tumor induction by virulent bacteria. LPS from site-binding strains was not effective if added to the plant wound shortly after the bacteria, and LPS from avirulent, non-site-binding strains of Agrobacterium was not inhibitory regardless of the order of addition. However, LPS and whole cells of avirulent strains NT1 and IIBNV6, which lack of Agrobacterim virulence plasmid, were inhibitory. Chromosomal deoxyribonucleic acid thus determines specificity of this essential component of the Agrobacterium infection process.
TL;DR: Staphylococcus aureus contains cell wall protein A as well as extracellular protein A, which have very similar amino acid compositions, electrophoretic mobilities and sizes.
Abstract: Staphylococcus aureus contains cell wall protein A as well as extracellular protein A. The two types of protein A have very similar amino acid compositions, electrophoretic mobilities and sizes. The release of extracellular protein A from exponentially growing bacteria is dependent on protein synthesis do novo and protein A is released directly after being synthesized on the ribosomes. Bacteria in the stationary phase, however, release protein A as a result of cell lysis. Protoplasts have been isolated which produce protein A as extensively as the intact bacteria but because of the absence of cell wall all the protein A is of the extracellular type. In the presence of puromycin, an enhancement of the formation of extracellular protein A is observed from cells also producing cell wall protein A.
TL;DR: The synthesis of several types of antibiotics was investigated in four strains of violet-pigmented bacteria belonging to the species Alteromonas luteo-violaceus; the macromolecular antibiotic acts at the respiratory level; it induces an increase of oxygen uptake and the production of peroxides by test bacteria.
Abstract: The synthesis of several types of antibiotics was investigated in four strains of violet-pigmented bacteria belonging to the species Alteromonas luteo-violaceus.Two of the strains simultaneously pr...
TL;DR: The results suggest that although the lipid moieties of the lipopolysaccharides in the cell wall of Gram-negative bacteria share cross-reactive immunodeterminant groups, these groups may not be accessible to antibody against them.
Abstract: Summary: Rabbit antisera were prepared against the heptoseless Re mutants, Salmonella minnesota R595 and S. typhimurium SL1102, as well as against purified R595 glycolipid coated on autologous erythrocytes. The antisera cross-reacted with the endotoxic glycolipids extracted from Re mutants of various bacterial strains, including S. minnesota R595, S. typhimurium SL1102, Escherichia coli D31m4, E. coli D21f2 and E. coli F515, as shown by passive haemagglutination and gel diffusion tests. The anti-Re sera also cross-reacted with the RESI preparations (a purified ‘lipid A’ fraction) from the endotoxic lipopolysaccharides of various heterologous smooth Gram-negative bacteria including Serratia marcescens, Pseudomonas fluorescens and E. coli 0127. However, the same antisera failed to protect mice against infection by Gram-negative bacteria such as Klebsiella pneumoniae type II, S. typhi 0901, P. aeruginosa 119 and E. coli. The results suggest that although the lipid moieties of the lipopolysaccharides in the cell wall of Gram-negative bacteria share cross-reactive immunodeterminant groups, these groups may not be accessible to antibody against them.
TL;DR: The initial observations indicating low serum K1 antibodies in the general population and the finding that K 1 antibodies are predominantly IgM in two animal species studied so far suggest that colostral K1 antibody may be important in conferring immunity to this disease.
Abstract: The conclusions from our studies to date may be summarized as follows. (1) Invasive E. coli strains causing neonatal meningitis are encapsulated. At least 80% of those strains inducing mengitis are K1 and approximately 40% of those strains isolated from infants with septicemia but without meningitis are also K1. Invasiveness is best related to the K1 antigen and not to E. coli O and H antigens. (2) The capsular content of CSF strains is not related to their invasiveness. In contrast to observations reporting higher K capsular polysaccharide content and molecular weight of E. coli invading the renal parenychma as compared with those E. coli confined to the bladder or in the stool, there were no differences among DSF K1 strains. Sepculation as to the mechanism of the invasive properties conferred by acidic capsular polysaccharides may be derived from the literature. Unencapsulated or "rough bacteria" are susceptible to the bactericidal action of agammaglobulinemice sera (15, 53). When injected into precolostral (agammaglobulinemic but complement containing), cesarian-delivered, and antigen-deprived piglets, unencapsulated bacteria are rapidly cleared from the circulation. In contrast, smooth bacteria injected into these same animals circulate without detectable splenic or hepatic clearance, multiply, and result in the death of these animals. The mechanism of the resistance of encapsulated bacteria has been postulated to be due to the inaccessibility of the deep somatic antigen structures capable of activating the alternate complement pathway system. Thus, opsoninization and other host complement-dependent activities may of necessity be antibody mediated for encapsulated bacteria. This complement resistance of encapsulated organisms may be quanititative and studies should be done to determine differences among various K1 E. coli strains. (3) K1 strains are widely prevalent among infants, children, and adults and are quickly transmitted to infants. In most cases the source of the infecting strain in diseased infants is the mother. However, transmission from attendants, demonstrable in our studies, is also a possible mechanism. (4) A protective role of serum anticapsular antibodies in animal models has been demonstrated. Our initial observations indicating low serum K1 antibodies in the general population and the finding that K1 antibodies are predominantly IgM in two animal species studied so far suggest that colostral K1 antibodies may be important in conferring immunity to this disease.
TL;DR: It is reported here that NAL specifically arrests the later stages of chromosomal replication in bacteria sensitive to the drug.
Abstract: NALIDIXIC acid (NAL) has been described as a specific inhibitor of bacterial DNA synthesis in vivo and in vitro1–3, but its mechanism of action on susceptible bacteria remains obscure. There is no evidence to indicate that NAL can bind to DNA3,4, and none of the enzymes known to be involved in DNA replication is affected by NAL in vitro3–6. But it is known that nalA mutants of Escherichia coli are resistant to the drug7, as are in vitro DNA replicative systems derived from such mutants8. This suggested that a comparative study of DNA replication in nalA mutants and otherwise isogenic bacteria should facilitate identification of the hitherto unknown NAL target. We report here that NAL specifically arrests the later stages of chromosomal replication in bacteria sensitive to the drug.
TL;DR: Viridin B was bactericidal to a Neisseria sicca strain, it was only bacteriostatic against a coagulase-negative staphylococcus, and had some unusual properties including heat lability, a narrow pH range of activity, and lack of adsorptive capacity to susceptible bacteria.
Abstract: Bacteriocin-like activities were detected in 78% of 120 alpha-hemolytic streptococcal isolates. Inhibitory substances from three such isolates (one Streptococcus sanguis strain and two S. mitis strains) were investigated further and termed viridins (A, B, and C). The viridins were unique among bacteriocins of gram-positive bacteria in that they inhibited many gram-negative bacteria in addition to inhibition of a variety of gram-positive organisms. Viridins were obtained in a cell-free state only after mechanical disruption of bacteriocinogenic cells but could not be isolated from supernatant fluids of cultures of such bacteria or from freeze-thaw liquor of agar on which the bacteria had been grown. Viridin B could be partially purified by ammonium sulfate precipitation and by gel filtration on a Sephadex G-100 column. This bacteriocin had some unusual properties including heat lability, a narrow pH range of activity, and lack of adsorptive capacity to susceptible bacteria. Although viridin B was bactericidal to a Neisseria sicca strain, it was only bacteriostatic against a coagulase-negative staphylococcus. Images
TL;DR: It is suggested that the mechanism of the pH-dependent antibiotic tolerance may involve either the production of a more stable plasma membrane or the suppression of the activity of a murein hydrolase(s) that catalyzes the antibiotic-induced lysis in E. coli cultures grown under neutral and acid pH conditions.
Abstract: Growth of E. coli at pH 5 protected the bacteria against the lytic effect of beta lactam antibiotics typically observed when the cells are grown at pH 7 or 7.5, i.e., the pH values routinely used in laboratory experiments. In contrast, the typical effects of beta lactam antibiotics on cellular shape and elongation and cell division appeared to be similar in cultures grown under neutral and acid pH conditions. The pH-dependent antibiotic tolerance can also be demonstrated with pneumococci, staphylococci, streptococci, and Bacillus subtilis. We suggest that the mechanism of the pH-dependent antibiotic tolerance may involve either the production of a more stable plasma membrane or the suppression of the activity of a murein hydrolase(s) that catalyzes the antibiotic-induced lysis; at least a fraction of these enzyme molecules may be localized at the cell surface and be accessible to experimental manipulation.
TL;DR: The mouse-virulent Salmonella typhimurium 395 MS, containing a complete lipopolysaccharide structure with S-specific repeating units, and the nonvirulent, LPS-defective mutant 395 MR 10 (chemotype Rd), derived from it, were studied for their tendency to interact with HeLa cells.
Abstract: The mouse-virulent Salmonella typhimurium 395 MS, containing a complete lipopolysaccharide (LPS) structure with S-specific repeating units, and the nonvirulent, LPS-defective mutant 395 MR 10 (chemotype Rd), derived from it, were studied for their tendency to interact with HeLa cells. In the definition of interaction no distinction has been made between intracellular and cell membrane-attached bacteria. R10 bacteria were found to have a greater tendency to interact than MS bacteria. This difference was seen as early as 1 h after the start of incubation, but it became more pronounced beyond 3 h. Heat-killed and ultraviolet-killed R10 bacteria interacted with HeLa cells less than living ones. Killed MS bacteria interacted to an extent similar to that of living ones. These results are discussed in relation to the susceptibility of the bacteria to phagocytosis by professional phagocytic cells and to the physiochemical properties of the bacteria as measured by their distribution in a two-polymer, aqueous-phase system.
TL;DR: Surgical-wound infections in mice for use in the evaluation of topical antibacterial agents appeared to reflect the dynamics of the total wound count, as determined by homogenization of biopsied tissue.
Abstract: Reproducible experimental surgical-wound infections in mice for use in the evaluation of topical antibacterial agents are described. The experimental would was created on the backs of mice by means of a midline incision and was infected by means of cotton sutures monocontaminated with Staphylococcus aureus or Pseudomonas aeruginosa . The course of these wound infections was followed by quantitation of surface bacteria through use of a surface rinse technique. Surface wound counts of the infecting organisms thus obtained appeared to reflect the dynamics of the total wound count, as determined by homogenization of biopsied tissue. Treatment of infected wounds with a placebo cream had only a slight effect on surface wound counts and on mortality in the case of the S. aureus infection but enhanced markedly the lethality of the P. aeruginosa infection. Images
TL;DR: The data presented suggest that altering the genetics of the wheat plant can change the root environment to favor the establishment of bacilli that exhibit N 2 -ase activity in pure culture.
Abstract: An asymbiotic bacillus possessing N 2 -ase activity and capable of growth on low-N media was consistently isolated from the rhizosphere of a chromosome substitution line of spring wheat in which a pair of chromosomes 5D from the cultivar Rescue had been substituted for those of ‘Cadet’. None of the bacilli were isolated from either of the two parent cultivars, Rescue and Cadet, or from the corresponding substitution line involving a homoeologous chromosome 5 B . Maximum C 2 H 2 reduction to C 2 H 4 by pure culture isolates was found to occur at a partial pressure of 0.2 atm C 2 H 2 . C 2 H 2 reduction was diminished in the presence of O 2 and nearly ceased at a partial pressure of 0.08 atm O 2 . The data presented suggest that altering the genetics of the wheat plant can change the root environment to favor the establishment of bacilli that exhibit N 2 -ase activity in pure culture.
TL;DR: It is suggested that adaptation of blood group-degrading enzymes to mucin structures in human colon ecosystems is chiefly by mutation-selection of comparatively small populations of constitutive enzyme-producing strains rather than by substrate induced enzyme synthesis in many strains.
Abstract: The autosomal dominant ABH secretor gene together with the ABO blood type gene control the presence and specificity of A, B, and H blood group antigens in human gut mucin glycoproteins. Certain obligate anaerobes in feces produce extracellular antigen-specific glycoside structures. We estimated the populations of these bacteria in feces of 22 healthy subjects by determining the greatest dilution of feces that yielded A, B, or H blood group-degrading enzyme activity after 24 h incubation in anaerobic cultures. Comparatively small populations of fecal bacteria produce blood group-degrading enzymes; their estimated populations were 10(8) per g or less in 21 subjects. Fecal populations of B-degrading bacteria were stable over time, and their population density averaged 50,000-fold greater in blood group B secretros than in other subjects. We present evidence that the greater fecal populations of B-degrading bacteria in B secretors is due in part to a competitive nutritional advantage gained by their ability to enzymatically cleave the B antigenic determinant alpha-D-galactose from gut mucins of B secretors. Fecal populations of bacteria producing A and H antigen-degrading enzyme activities were comparable in all subjects to the fecal population of B-degrading bacteria in B secretors. The large populations of fecal anaerobes may be an additional source of A antigen substrate for A-degrading bacteria; thus, antigens cross-reacting with A antigen were detected on cell walls of anaerobic bacteria from 3 of 10 cultures inoculated with 10(-10) g feces. Bacteria producing B-degrading activity likely represent a separate population from those producing A- or H-degrading activity since their fecal populations differed numerically in 14 subjects. These findings suggest that adaptation of blood group-degrading enzymes to mucin structures in human colon ecosystems is chiefly by mutation-selection of comparatively small populations of constitutive enzyme-producing strains rather than by substrate induced enzyme synthesis in many strains.
TL;DR: The effective inhibition by TM of peptidoglycan synthesis in a cell-free system of Micrococcus lysodeikticus is reported, suggesting that the target point of TM in bacteria resides in the cell wall synthesis.
TL;DR: Some unsaturated fatty acids were found to inhibit the growth of Staphylococcus aureus and the presence of a plasmid conferring resistance to tetracycline did not make the bacterium more sensitive to inhibition by linoleic or linolenic acids.
Abstract: Summary: Some unsaturated fatty acids were found to inhibit the growth of Staphylococcus aureus. Their effectiveness was related both to the degree of unsaturation and to the configuration of the molecule about the double bonds. Both linoleic acid and linolenic acid increased the proportion of plasmid-negative bacteria in a growing culture of bacteria containing a penicillinase plasmid. This was not due to a ‘curing’ effect of the fatty acids but was the result of greater sensitivity of the growth of bacteria containing penicillinase plasmid to inhibition by the unsaturated fatty acids. The presence of a plasmid conferring resistance to tetracycline, however, did not make the bacterium more sensitive to inhibition by linoleic or linolenic acids.
TL;DR: Screening of protein-producing bacteria was conducted to systematically study the ubiquitous nature of the extracellular production of proteins and their excretion mechanisms and many good protein producers including five excellent ones were found to be gram-positive rod and probably belong to Bacillus species.
Abstract: Screening of protein-producing bacteria was conducted to systematically study the ubiquitous nature of the extracellular production of proteins and their excretion mechanisms. A very simple and efficient test revealed that about 15% of bacteria tested (total 1200 strains) accumulated some protein under the cultural conditions employed. Among protein-excretors, five strains produced a large amount of protein in the liquid shake culture.Many good protein producers including five excellent ones were found to be gram-positive rod and probably belong to Bacillus species. An acid-insoluble product by one of the hyper-protein producers was identified as a protein mixture. Good producer was not found among the known 15 species of bacteria. The implication of these findings is discussed.