Plant growth regulatory metabolites from novel actinomycetes

Metabolites from 796 isolates of aerobic actinomycetes were screened for plant growth regulatory properties using an algal bioassay. These included 266 isolates ofStreptomyces, 28 unidentified actinomycetes, and 502 isolates of novel actinomycetes represented by 18 genera. Algal growth inhibition of 30% was observed with 60 isolates, 37 of which belonged to the genusStreptomyces. Among other inhibitors were 8 isolates ofActinomadura, 6 ofActinoplanes, 2 each of the generaThermomonospora, Streptoverticillium, andPromicromonospora, and 3 unidentified. Metabolites from 70 isolates promoted algal growth by 20%. These included 13 isolates ofMicromonospora, 11 ofStreptomyces, 6 ofNocardia, 5 ofActinomadura, and 4 each ofRhodococcus andThermomonospora. Sixteen unidentified isolates; 3 isolates ofPromicromonospora; 2 isolates each ofActinoplanes, Streptosporangium, andOerskovia; and 1 of Thermoactinomyces peptonophilus-like organism andSaccharomonospora viridis also promoted the algal growth by 20%. The plant growth inhibitory properties of 9 actinomycetes and the growth promoting properties of 6 were demonstrable during the secondary screening on higher plants using chemicals extracted from the culture broth. The metabolites fromMicromonospora, Nocardia, Rhodococcus, Streptosporangium, andOerskovia isolates were associated with plant growth promotion only; those fromStreptomyces were most frequently involved with the growth inhibition.This is Michigan Agriculture Experiment Station Journal Article No. 12191.     

Comparison of the effect of antibiotic substances on sclerotia of Mycosphaerella ligulicola and Colletotrichum coccodes

Summary Sclerotia ofColletotrichum coccodes tolerated much higher concentrations of actidione in agar than did sclerotia ofMycosphaerella ligulicola. With increase in concentration of the antibiotic sclerotia of both species took longer to germinate. Increased resistance of both species to actidione developed after growth of a single generation on media containing the antibiotic. Sclerotia ofC. coccodes survived 5 days immersion in a bacterial culture filtrate whereas scleroia ofM. ligulicola ceased to be viable after a similar period.Sclerotia ofC. coccodes andM. ligulicola exhibited strand and loose types of formation respectively. The degree of resistance of these sclerotia to antibiotic substances was correlated with both longevity in soil and type of formation, but, in general, there is unlikely to be a relationship between structure of the sclerotium and longevity.     

Meiotic studies ofElymus nutans andE. jacquemontii (Poaceae,Triticeae) and their hybrids withPseudoroegneria spicata and seventeenElymus species

Hybridizations ofElymus nutans andE. jacquemontii were carried out with one species ofPseudoroegneria (S genome), and 20Elymus species, each containing either of the SH, SY, SYH, or SYW genomes. Chromosome configurations were analysed at metaphase I of the two target taxa and their interspecific hybrids. It is concluded that (i)E. nutans is an allohexaploid containing the SYH genomes, andE. jacquemontii is an allotetraploid having the SY genomes; (ii) the genomic affinity is associated with the geographic distance between the species studied; (iii) minor genomic structural rearrangements have occurred within the hexaploid taxon ofE. nutans.     

Extraction and preliminary characterizaion of a mycobacteriolytic preparation (stazyme) from aStaphylococcus strain: mycobactericidal activity and its use in rapid extraction of mycobacterial DNA

The clear culture filtrate from 1-L culture of a laboratory contaminant ofStaphylococcus (coagulase^– strain, designated Clavelis) was filtered, concentrated, dialyzed, and the proteins were precipitated. The precipitate was washed, concentrated, and aliquoted (about 4 mg of total proteins/ml, designated as Stazyme). The crude preparation was subjected to gel filtration on Sephadex G-75, and the fractions were screened for their lytic ability againstMycobacterium smegmatis. Native proteins in the stazyme were electrophoretically separated, electroeluted, and their lytic activity againstM. smegmatis was compared with parallel controls (partially purified proteins extracted from the same quantity of the uninoculated bacterial growth medium). Only stazyme preparations caused significant growth inhibition ofM. smegmatis, M. chelonae, M. xenopi, M. tuberculosis, andM. kansasii. Stazyme essentially possessed a lytic activity measured with purifiedM. smegmatis andMicrococcus lysodeikticus cell walls and showed high bactericidal activity againstM. smegmatis, M. chelonae, andM. tuberculosis. It was also able to rapidly lyse intactM. smegmatis organisms, permitting significant yield of mycobacterial DNA.     

Effects of random motility on growth of bacterial populations

A spatially distributed mathematical model is developed to elucidate the effects of chemical diffusion and cell motility as well as cell growth, death, and substrate uptake on steady-state bacterial population growth in a finite, one-dimensional, nonmixed region. The situation considered is growth limited by a diffusing substrate from an adjacent phase not accessible to the bacteria. Chemotactic movement is not considered in this paper; we consider only randomwalk-type random motility behavior here. The following important general concepts are suggested by the results of our theoretical analysis: (a) The significance of random motility effects depends on the magnitude of the ratio/kL ², where is the bacterial random motility coefficient,k is the growth rate constant, andL is the linear dimension of the confined growth region. (b) In steady-state growth in a confined region, the bacterial population size decreases as increases. (c) The effect of on population size can be great; in fact, sometimes relative population sizes of two species can be governed primarily by the relative values of rather than by the relative values ofk.     

Utilization of a wood-based syrup as a fermentation carbon source

Summary An industrial by-product stream consisting primarily of - and -methyl xylosides supported microbial growth provided the treated syrup was diluted such that the osmotic pressure was within the range tolerated by the particular microorganism used. A culture screening study identified two organisms that efficiently utilized both - and -methyl xyloside. Xylose, -, and -methyl xylosides were all utilized simultaneously during batch growth ofArthrobacter sp. in a controlled-pH fermentor, although xylose was consumed faster than either xyloside. In addition,Arthrobacter sp. produced glucose isomerase when grown on the syrup.     

Alloxan: A growth accelerator for a nitrogen-fixing blue-green alga

Effect of Alloxan was studied on a nitrogen-fixing blue-green alga: Westiellopsis prolifica in pure cultures. Concentrations of Alloxan, 10 g to 50 g/ml stimulate the growth of the alga and increase the chlorophyll, carotin and phycocyanin content of the cultures.     

Problems in estimating growth rates of marine phytoplankton from short-term14C assays

Growth rate estimates () of phytoplankton populations that were sampled from nitrogen-limited continuous cultures and then incubated for short durations in batch culture with added¹⁴C-HCO₃ ^– were significantly different than steady-state growth rates () for 3 of 5 marine phytoplankton species. Two diatoms,Thalassiosira weissflogii andChaetoceros simplex, displayed virtually identical growth rates (=) over a wide range of, whereas for a third diatom,Phaeodactylum tricornutum, was overestimated by an average of 40% compared to. In contrast, was underestimated by the¹⁴C technique for the two remaining species: up to 40% at a steady-state of 1.0 day^–1 for the chlorophyteDunaliella tertiolecta and up to 100% at of 1.4 day^–1 for the haptophytePavlova lutheri. For the latter two species the divergence between and appeared to increase with increasing steady-state. A simple model of labeled and total carbon flow between the aqueous phase and cellular biomass was constructed to demonstrate that respiration was negligible when=, but was significant when>. In the cases in which<, a rapid physiological alteration presumably took place once the steady state was disturbed and cells were placed in the incubation chambers, which perhaps was related to the nutritional state of the cultures at the time of sampling. Questions thus are raised regarding our ability to measure accurately primary productivity from shipboard experiments with confined samples of phytoplankton from nutrient-impoverished waters that probably are less hardy than the laboratory cultures used in these studies.     

Fromβ-lactams toα- andβ-amino acid derived peptides

Summary The potential of-lactams as intermediates for the access to- and-amino acid-derived peptides is shortly reviewed, with major focus on the technologies developed in our group. The two general strategies lie, on one side, in the oxidative ring expansion of 3-hydroxy-lactams toN-carboxy-amino acid anhydrides or Leuch's anhydrides and subsequent coupling with-amino acid esters and, on the other side, in the nucleophilic ring opening ofN-Boc--lactams. Both approaches have been successfully applied to the synthesis of,-diamino acid,-amino--hydroxy acid, polyhydroxylated-amino acid,,-disubstituted-amino acid,-amino acid,-amino--hydroxy acid and,-disubstituted-amino acid derived peptides. Because of the mild reaction conditions needed for the above transformations and the highly stereoselective procedures employed for the construction of the starting-lactam ring, the whole process allows the production of optically pure final products.     

Evolution alpiner Populationen vonEuphrasia (Scrophulariaceae): Die mittel- bis kleinblütigen,drüsenhaarigen Arten

A more precise taxonomic concept ofE. hirtella and its infraspecific synonymy is presented. Its diploid nature (2n = 22) is confirmed. Within the European area ofE. hirtella five different races may be recognised: typical, brandisii, capitulata, Rofan and Bretagne. Taxonomic rank is not yet attributed to these races. The heterogeneous taxonomic assembly E. drosocalyx is disentangled. The type refers to products of hybrid introgression ofE. rostkoviana-characters (long glandular hairs) intoE. minima.

Former contributions of this series areEhrendorfer & Vitek (1984) andGreilhuber & al. (1984).     

Factors affecting the synthesis and distribution ofβ-lactamase inMycobacterium smegmatis SN2 cultures

A high level of extracellular -lactamase activity was detected in cultures ofMycobacterium smegmatis SN2. The extracellular distribution of the enzyme varied with growth conditions such as additional carbon source and pH of the medium. Addition of chloramphenicol tothe culture inhibited the increase in the extracellular -lactamase activity. Cell wall damage or autolysis may be responsible for the extracellular -lactamase activity.     

2-Bromoethanesulfonate: A selective agent for isolating resistantMethanosarcina mutants

Sodium 2-bromoethanesulfonate (BES), a structural analog of 2-mercaptoethanesulfonate (coenzyme M), inhibited methanogenesis and growth ofMethanosarcina strain 227 in the presence of H₂/CO₂, methanol, or acetate. A single exposure to 24 M BES was sufficient to produce cultures resistant to 240 M BES. Wild-type cultures inhibited by 200 M BES (or less) resumed growth and methane production when coenzyme M (coM) was added to the culture medium. Cultures incubated one week or longer with 200 M BES (or less) spontaneously resumed growth and methanogenesis in the presence of H₂/CO₂, methanol, or acetate without added coM. BES resistance was heritable and not the result of inactivation or decomposition of BES. BES resistance acquired on one methanogenic substrate was retained when cells were grown on a different methanogenic substrate. However, BES resistance did not confer multiple resistance to other halomethane compounds such as chloroform, 2-bromoethanol, 2-bromopropionic acid, and chloramphenicol. BES resistance varied in two other genera of methanogens tested. One strain ofMethanospirillum hungatei was very sensitive to BES, and no resistant mutants were demonstrated. One strain ofMethanobacterium formicicum, however, was resistant to 200 M BES without any known prior exposure to BES.     

Rapid micropropagation of <Emphasis Type="Italic">Curcuma longa</Emphasis> using bud explants pre-cultured in thidiazuron-supplemented liquid medium

Multiple shoots of Curcuma longa were induced by culture of bud explants for 1week in Murashige and Skoog (MS) liquid medium supplemented with 72.64M thidiazuron (TDZ) prior to culture on MS gelled medium without growth regulator for 8weeks. The regeneration rate was up to 11.4±1.7shoots/explant. Rooting was spontaneous and the regenerated plants were successfully transferred to soil. This protocol can be an alternative for rapid micropropagation of C. longa used for phytomedicine raw material production.     

Reversal of cerulenin inhibition ofMycobacterium avium by octanoate

Mycobacterium avium is an opportunistic pathogen that may cause either localized or, in persons with acquired immune deficiency syndrome (AIDS), disseminated disease. Under certain conditionsM. avium exhibits a requirement for fatty acid for maximum production of colony-forming units (CFU). However, cerulenin, a drug that inhibits fatty acid synthetase, inhibited the growth ofM. avium LM1 (serovar 1) with a minimal inhibitory concentration of 10 g/ml regardless of oleic acid supplementation at 50 g/ml. Cerulenin at 10 g/ml also inhibited the growth of five other strains ofM. avium isolated from AIDS patients. Octanoate, oleate, and palmitate, individually or in two-way combinations, were tested for ability to reverse the effect of cerulenin. Octanoate at 50 g/ml could reverse the bactericidal effect of cerulenin at 10 g/ml and the bacteriostatic effect of the drug at 5 g/ml. Because cerulenin when effectively inhibiting production of CFU also prevented cell elongation, the data suggest that octanoate, or a metabolic product, is critical to cell division ofM. avium.     

Isozyme polymorphism ofβ-glucosidase inAspergillus nidulans

Electrophoretic analysis of the distribution of various electromorphs at different -glucosidase zones was carried out in natural populations ofA. nidulans, theA. nidulans group, and various species belonging to the genusAspergillus from diverse geographical areas of India. The data show the existence of three segregating zones for -glucosidase, designated -GluI, -GluII and -GluIII. All three zones are present in wild isolates ofA. nidulans, and only two, i.e., -GluI and -GluIII, in theA. nidulans group and -GluII and -GluIII in different species ofAspergillus exceptA. terreus, A. flavus, andA. brevipes, where only -GluIII is present. Overall nine electromorphs are observed at -GluI, three at -GluII, and six at -GluIII zones, respectively, It can be concluded that there may be three structural genes for -glucosidase coding the three polymorphic zones inA. nidulans.This research work was supported by the Council of Scientific and Industrial Research (CSIR), New Delhi.     

Effect of ionophores on the processing of theβ-amyloid precursor protein in different cell lines

Summary 1. Alzheimer's disease is characterized by the deposition in the brain of extracellular amyloid plaques and vascular deposits consisting mostly of amyloid-peptide (A). A, a polypeptide of 39–43 amino acids (M _r, 4 kDa), is derived proteolytically from a family of proteins of 695–770 amino acids (M _r, 110–140 kDa) called-amyloid precursor protein (APP).2.APP, an integral membrane glycoprotein, is extensively posttranslationally modified within the endoplasmic reticulum (ER) and various Golgi compartments.APP is cleaved by proteases in either the trans-Golgi network or the post-Golgi apparatus and then secreted as a truncated soluble form into the conditioned media of cultured cells and cerebrospinal fluid samples from human subjects.APP can be processed either by an antiamyloidogenic secretory pathway or by an endosomal/lysosomal pathway.3. I studied the effect of two ionophores on the processing ofAPP in cultured cells. Monensin and, in some cases, ammonium chloride increase the intracellular accumulation ofAPP in several cell lines and may alter its processing. Monensin, which had the most consistent effects, also inhibited secretion ofAPP in a differentiated (growth factor mediated) cell line. Nigericin, with greater K⁺ selectivity, was less able to alter the accumulation and possible processing of the protein.4. These results suggest that the increase in the accumulation of intracellularAPP observed after treating cells with ionophores has some specificity. The selective effect of these ionophores on the metabolism ofAPP may provide a model system to analyze the pathways for studying maturation, secretion, and degradation ofAPP.     

Meiotic analysis ofElymus caucasicus,E. longearistatus,and their interspecific hybrids with twenty-threeElymus species (Triticeae,Poaceae)

Interspecific hybridizations were carried out between the two tetraploidsElymus caucasicus andE. longearistatus, and 23 tetraploids and hexaploids ofElymus containing SH, SY, SYH, and SYW genomes and representing various geographical regions. Meiotic pairing was studied in the two target species and their hybrids. It is concluded from this study that (i) interspecific hybridization is fairly easy to perform although strong reproductive barriers exist between the species; (ii)Elymus caucasicus andE. longearistatus are allotetraploids, and share the diverged SY genomes; (iii) the divergence of SY genomes is correlated with the geographic distance between theElymus spp. studied.     

Biological individuality and disease

The concept of predisposition in medicine is ancient, and the term diathesis was used to express it since the days of Hippocrates and, especially, of Galen.The concept of diathesis was enormously popular throughout the nineteenth century, despite the vagueness of its actual meaning. It was clarified only in the early years of the twentieth century (1902), when it was however losing its clinical relevance, by a replacement of the concept ofchemical individuality by A.E. Garrod, followed thirty years later by the concept ofinborn factors in disease (1931).Molecular knowledge of the biological individuality of human beings, highlighted particularly by the discovery of the MHC (Major Histocompatibility Complex) during the last 30–35 years, and substantially HLA (Human Leukocyte Antigens), has offered a new and better understanding of the relationship between theself and thenot-self, as well as of various diseases, especially if they are favored by some immune dyshomeostatis.Extensive knowledge oftransplants-their immune fate of take or rejection, possibly of GVHD-have allowed mankind to consider each human being as abiological Ego, unique in his antigenic-molecular structure. But most of all, the demonstration of the fact that certain HLA antigens can be significantly associated with a greater predisposition, on the part of individuals bearing these antigens, toward contracting certain diseases, reconsiders in precise molecular terms the concept of predisposition and therefore, perhaps, in a new light, even the concept of diathesis, providing an actual logical basis for it.     

An account of the genus pythium Pringsheim in India

Summary Of the 20 species ofPythium reported from India, not more than seven assume parasitic role inciting mainly diseases in seed bed and sometimes in the fields such as damping-off, seedling blights and foot rots. The paper gives a brief account of the taxonomy of the Indian species and methods of controlling the diseases incited by them.     

Kinetics of growth and lactic acid production in continuous and batch culture

Summary In a lactic acid fermentation by Streptococcus faecalis, the specific consumption rate of glucose (v) and the specific production rate of lactic acid () were represented by the following simple equations as functions of the specific growth rate (): 1/=(1/) + 1/ = (1/) + By use of data from a batch culture, these two equations were derived from enzyme kinetics of the product inhibition. These equations were successfully applied to the results of batch culture and chemostat culture. In addition, calculation of ATP yield by these equations agreed with the experimental results better than the conventional Leudeking-Piret type equation, which includes two terms associated with growth and not with growth. Correspondence to: H. Ohara