Strain LP Research Articles

Comparative lactic acid fermentation with five Lactobacillus strains of supernatants made of extruded and saccharified chickpea flour

SummaryGlucose‐rich supernatants were developed based on the enzymatic hydrolysis of raw and extruded chickpea flours first treated with alcalase® and then with a combination of alpha‐amylase and amyloglucosidase or only amyloglucosidase. The optimum treatments were the extruded hydrolysates further treated with amyloglucosidase ‘EF(AMG)’, or the raw chickpea flour treated with a combination of alpha‐amylase and amyloglucosidase ‘RF (Amyl+AMG)’. The resulting supernatants were further fermented with five different strains of Lactobacillus and monitored for 24 h in terms of pH, titratable acidity, and microbial counts. Also, the glucose content and oligosaccharides, total protein, and viability were determined. Both supernatants presented a successful fermentation as estimated by the pH drop (<4.2), lactic acid produced (>0.7%), and microbial counts 9 log (CFU mL−1) which increased up to 5 log during the 24 h fermentation. However, the EF(AMG) supernatant induced fewer reductions in glucose and protein contents in comparison to the RF (Amyl+AMG) counterpart. Among bacteria, the strain Lp 29 in EF(AMG) showed the fastest growth rate (K) and the highest residual protein. In all cases, the proposed technology enhanced the growth of five Lactobacillus strains by taking advantage of the hydrolyzed chickpea chemical composition.

Molecular Identification and Selection of Probiotic Strains Able to Reduce the Serum TMAO Level in Mice Challenged with Choline.

Trimethylamine oxide (TMAO) originates from trimethylamine (TMA), which is oxidized in the liver by hepatic flavin-containing monooxygenases (FMO3). TMA is produced by its dietary precursors such as choline, carnitine, and phosphatidylcholine by gut microbiota. TMAO attracts attention, identified as a novel and independent risk factor for promoting obesity, atherosclerosis and cardiovascular disease (CVD), chronic kidney disease (CKD), insulin tolerance, and colon cancer. Probiotics have been considered as live microorganisms, providing benefits to their host when they are given in sufficient quantities and administered continuously. The objective of this study is to suggest a method to select potential probiotic strains to reduce the serum concentration of TMAO in mice fed with choline. In this work, we chose three lactobacilli with strong adherence capability, and fed multistrain formula (MF) to the mice challenged with choline. On days 7, 14, and day 28, it was found that the MF-containing L. amylovorus LAM1345, Lpb. plantarum LP1145, and Lim. fermentum LF33 showed a significant reduction in serum TMAO and TMA levels. For the single strains, LP1145 reduced TMAO on days 14 and 28, and strain LAM1345 reduced TMAO significantly on days 7 and day 14. For strain LF1143 from strain LF33, it showed no significant effect on TMAO and TMA. Thus, MF showed the best effect, which may be due to the additive and synergetic effect and the contribution of strain LP1145 and LAM1345. Finally, for the LAM1345 and LP1145 strains, we used molecular identification and typing methods to assure that these two strains are unique strains. The methods used for LAM 1345 were leader peptidase A (lepA) gene analysis and phylogenetic analysis, while for strain LP 1145and other strains of Lpb. plantarum subsp. plantarum sequences were compared using the whole-genome multilocus sequence typing (wgMLST) method.

The effects of Lactobacillus plantarum with feruloyl esterase-producing ability or high antioxidant activity on the fermentation, chemical composition, and antioxidant status of alfalfa silage

This study was aimed to evaluate the effects of an efficient ferulic acid esterase-producing Lactobacillus plantarum A1 and an antioxidant strain L. plantarum 24-7 on fermentation, chemical composition, antioxidase activity and antioxidant status of alfalfa silage. Freshly chopped and wilted alfalfa with about 30 % dry matter (DM) was treated either without (CON) or with L. plantarum A1 (Lp A1), L. plantarum 24-7 (Lp 24-7), and a reference strain of L. plantarum MTD/1 (Lp MTD/1) at an application rate of 1 × 106 CFU/g fresh weight, respectively, and ensiled for 7, 14, 30, 60, and 90 d. All inoculants improved silage quality as indicated by low pH, high lactic acid concentration, and lactic acid/acetic acid compared to the CON from 7 d to 90 d of ensiling. After 90 d of ensiling, the lowest DM loss and non-protein N were observed in the Lp A1 inoculated silage. Inoculation of Lp A1 also decreased the neutral detergent fiber, acid detergent fiber, and acid detergent lignin concentrations in the later period of ensiled alfalfa, and increased ferulic acid concentration during all ensiling duration. The highest ferulic acid concentration was detected in Lp A1 treated silage after 30 d (P < 0.05). In addition, the total antioxidant capacity and glutathione peroxidase activity in the Lp A1 and Lp 24-7 inoculated silages were higher than that in the CON and Lp MTD/1 silages from 30 d to 90 d of ensiling. However, lower lipoxygenase activity was found in Lp A1 and Lp 24-7 inoculated silages during the whole fermentation process. Both Lp A1 and Lp 24-7 improved the total fatty acid concentration and the proportion of polyunsaturated fatty acids in total fatty acid of ensiled alfalfa when compared with the CON and Lp MTD/1 silages after 90 d of fermentation (P < 0.05). Therefore, inoculation of ferulic acid esterase-producing Lp A1 or antioxidant strain Lp 24-7 not only improved the fermentation quality and chemical composition of ensiled alfalfa but also enhanced the antioxidant status of the silage.

Lactobacillus parafarraginis ZH1 producing anti-yeast substances to improve the aerobic stability of silage.

Enhancing the aerobic stability of silage is very important in silage production. The objective of this study was to compare the roles of a new bacterial strain Lactobacillus parafarraginis ZH1 with Lactobacillus plantarum Chikuso-1 (LP) and Lactobacillusbuchneri NCIMB 40788 (LB) in improving the aerobic stability of oat silage and identify the anti-yeast substances produced by them. After ensiled for 45days, either inoculated silages or control silage were of pH values lower than 4.2. The control and LP inoculated silage had poorer aerobic stability than LB and ZH1 inoculated ones (p<0.05). ZH1 inoculated silage produced more acetic acid, benzoic acid and hexadecanoic acid than LB inoculated one and had the best aerobic stability (p<0.05). In MRS medium, strain ZH1 produced more hexadecanoic acid than LP and LB strains, more benzoic acid than strain LP (p<0.05), and the equal amount of benzoic acid to LB (p>0.05). In addition, benzoic acid and hexadecanoic acid had low minimal inhibitory concentrations to target yeasts in the pure culture. In conclusion, L.parafarraginis ZH1 had stronger anti-yeast potential and more effectively improved the aerobic stability of silage than other strains used in this study.

Small RNA-Omics for Virome Reconstruction and Antiviral Defense Characterization in Mixed Infections of Cultivated Solanum Plants.

In plants, RNA silencing-based antiviral defense generates viral small RNAs (sRNAs) faithfully representing the viral genomes. We employed sRNA sequencing and bioinformatics (sRNA-omics) to characterize antiviral defense and to reconstruct the full genomic sequences and their variants in the evolving viral quasispecies in cultivated solanaceous plants carrying mixed infections. In naturally infected Solanum tuberosum (potato), one case study revealed a virome comprising Potato virus Y (genus Potyvirus) and Potato virus X (genus Potexvirus), which was reconstructed by de novo-assembling separate genome-size sRNA contigs. Another case study revealed a virome comprising NTN and O strains of Potato virus Y, whose sRNAs assembled in chimeric contigs, which could be disentangled on the basis of reference genome sequences. Both viromes were stable in vegetative potato progeny. In a cross-protection trial of Solanum lycopersicum (tomato), the supposedly protective mild strain CH2 of Pepino mosaic virus (genus Potexvirus) was tested for protection against strain LP of the same virus. Reciprocal mechanical inoculations eventually resulted in co-infection of all individual plants with CH2 and LP strains, reconstructed as separate sRNA contigs. LP invasions into CH2-preinfected plants and vice versa were accompanied by alterations of consensus genome sequences in viral quasispecies, indicating a potential risk of cross-protection measures. Additionally, the study also revealed, by reconstruction from sRNAs, the presence of the mechanically nontransmissible Southern tomato virus (genus Amalgavirus) in some plants. Our in-depth analysis of sRNA sizes, 5'-nucleotide frequencies and hotspot maps revealed similarities in sRNA-generating mechanisms in potato and tomato, differential silencing responses to virome components and potential for sRNA-directed cross-targeting between viral strains which could not, however, prevent the formation of stable viromes.

Immunomodulatory Effects of Different Lactic Acid Bacteria on Allergic Response and Its Relationship with In Vitro Properties.

Some studies reported that probiotic could relieve allergy-induced damage to the host, but how to get a useful probiotic is still a challenge. In this study, the protective effects of three lactic acid bacteria (La, Lp and Lc) were evaluated in a mouse model, and its relationship with the in vitro properties was analyzed. The in vitro results indicated that La with the capacity to inhibit IL-4 production could have a better anti-allergy effect in vivo than two others. However, the animal trials showed that all LAB strains could alleviate allergen-induced airway inflammation. Among them, LAB strain Lp had a better effect in inhibiting allergic response through a modulation of Th1/Th2 balance and an increase of regulatory T cells. This difference could be explained by that different LAB strains have a strain-specific effect on gut microbiota closely associated with host immune responses. Finally, this study did not only obtain an effective anti-allergy probiotic strain via animal study, but also indicate that probiotic-induced effect on intestinal microbiota should be considered as an important screening index, apart from its inherent characteristics.

An animal component free medium that promotes the growth of various animal cell lines for the production of viral vaccines

IPT-AFM is a proprietary animal component free medium that was developed for rabies virus (strain LP 2061) production in Vero cells. In the present work, we demonstrated the versatility of this medium and its ability to sustain the growth of other cell lines and different virus strains. Here, three models were presented: Vero cells/rabies virus (strain LP 2061), MRC-5 cells/measles virus (strain AIK-C) and BHK-21 cells/rabies virus (strain PV-BHK21). The cell lines were first adapted to grow in IPT-AFM, by progressive reduction of the amount of serum in the culture medium. After their adaptation, BHK-21 cells grew in suspension by forming clumps, whereas MRC-5 cells remained adherent. Then, kinetics of cell growth were studied in agitated cultures for both cell lines. In addition, kinetics of virus replication were investigated.

Lack of Galactose or Galacturonic Acid in Bradyrhizobium japonicum USDA 110 Exopolysaccharide Leads to Different Symbiotic Responses in Soybean

Exopolysaccharide (EPS) and lipopolysaccharide (LPS) from Bradyrhizobium japonicum are important for infection and nodulation of soybean (Glycine max), although their roles are not completely understood. To better understand this, we constructed mutants in B. japonicum USDA 110 impaired in galactose or galacturonic acid incorporation into the EPS without affecting the LPS. The derivative LP 3010 had a deletion of lspL-ugdH and produced EPS without galacturonic acid whereas LP 3013, with an insertion in exoB, produced EPS without galactose. In addition, the strain LP 3017, with both mutations, had EPS devoid of both galactosides. The missing galactosides were not replaced by other sugars. The defects in EPS had different consequences. LP 3010 formed biofilms and nodulated but was defective in competitiveness for nodulation; and, inside nodules, the peribacteroid membranes tended to fuse, leading to the merging of symbiosomes. Meanwhile, LP 3013 and LP 3017 were unable to form biofilms and produced empty pseudonodules but exoB suppressor mutants were obtained when LP 3013 plant inoculation was supplemented with wild-type EPS. Similar phenotypes were observed with all these mutants in G. soja. Therefore, the lack of each galactoside in the EPS has a different functional effect on the B. japonicum-soybean symbiosis.

A novel animal-component-free medium for rabies virus production in Vero cells grown on Cytodex 1 microcarriers in a stirred bioreactor

Vero cells growth and rabies production in IPT-AF medium, a property animal-component-free medium are described in this work. Kinetics of cell growth and rabies virus (strain LP 2061) production were first conducted in spinner flasks. Over eight independent experiments, Vero cell growth in IPT-AF medium, on 2 g/l Cytodex 1 was consistent. An average Cd (cell division number) of 3.3+/-0.4 and a specific growth rate micro of 0.017+/-0.006 h(-1) were achieved. Such performances were comparable to those obtained in serum-containing medium (MEM+10% FCS). Rabies virus production on Vero cells in IPT-AF medium was also optimised in spinner flasks. The effects of multiplicity of infection (MOI), regulation of glucose level at 1 g/l and cell washing step, were investigated. The highest virus titer was achieved when the cells were infected at an MOI of 0.1; this level was equal to 10(7) FFU/ml. The step of medium exchange before cell infection can be omitted; nevertheless in this case glucose level should be maintained at 1 g/l to avoid a decrease of specific virus productivity. Process optimisation in a 2-l stirred bioreactor pointed out that the aeration mode was the prominent parameter that affected cell growth in IPT-AF medium and on Cytodex 1 microcarriers. An acceptable level of cell density (cell density level of 1.5x10(6) cells/ml) was achieved when cells were grown in batch mode and using headspace aeration. Nevertheless, this aeration mode is not optimal for large-scale culture. The addition of Pluronic F68 at 0.1% at 24 h post inoculation as well as the switch from surface aeration mode to the sparged mode, 2 days after the start of the culture, had markedly improved cell growth performance. A cell density level of 5.5x10(6) cells/ml was reached when cells were grown in a 2-l bioreactor, on 3 g/l Cytodex 1 in IPT-AF medium and using the recirculation culture mode. Cell infection at an MOI of 0.1 and using perfused culture, resulted in a maximal virus titer of 3.5x10(7) FFU/ml. The activity of the pooled inactivated rabies virus harvests showed a protective activity that meets WHO requirements.

In‐Furrow Inoculation and Selection for Higher Motility Enhances the Efficacy of Bradyrhizobium japonicum Nodulation

The issue of competition for nodulation has received much attention in studies on soybean [Glycine max (L.) Merr.] crops because native soil rhizobia often preclude nodulation of inoculated high‐quality strains. In this work, soil placement and enhanced motility of Bradyrhizobium japonicum were investigated as strategies to improve the competitiveness of soybean inoculants applied in the presence of large populations of native (or indigenous) soybean‐nodulating rhizobia. The first strategy might allow for the enhanced distribution of inoculant rhizobia in the surface soil, compared with inoculant that is directly applied to soybean seed, while the second strategy is expected to enhance root colonization. The effects of soil placement and enhanced bacterial motility on percentage nodule occupation, grain yield, and grain N contents were examined during the 2004–2005 soybean season at three locations in Argentina, comprising soils classified as entic hapludol, argillic pelludert, and typical argiudol. The experimental design was a randomized complete block design, and main effects and interactions were also analyzed with a factorial design. Strain LP 3008, previously selected for increased motility, was more effective than the commonly inoculated strain E 109. While E 109 occupied, on average, 13.2% of nodules with seed inoculation, LP 3008 occupied 28.2%. In comparison, in‐furrow inoculation yielded 24.2 and 37.2% average nodule occupancies for E 109 and LP 3008, respectively. However, these gains in nodulation efficacy lead to a modest, nonsignificant yield increase, and grain N content was unaffected.

Improved soybean root association of N-starved Bradyrhizobium japonicum.

In this study, we addressed the effects of N limitation in Bradyrhizobium japonicum for its association with soybean roots. The wild-type strain LP 3001 grew for six generations with a growth rate of 1.2 day(-1) in a minimal medium with 28 mM mannitol as the carbon source and with the N source [(NH(4))(2)SO(4)] limited to only 20 microM. Under these conditions, the glutamine synthetase (GS) activity was five to six times higher than in similar cultures grown with 1 or 0.1 mM (NH(4))(2)SO(4). The NtrBC-inducible GSII form of this enzyme accounted for 60% of the specific activity in N-starved rhizobia, being negligible in the other two cultures. The exopolysaccharide (EPS) and capsular polysaccharide (CPS) contents relative to cell protein were significantly higher in the N-starved cultures, but on the other hand, the poly-3-hydroxybutyrate level did not rise in comparison with N-sufficient cultures. In agreement with the accumulation of CPS in N-starved cultures, soybean lectin (SBL) binding as well as stimulation of rhizobial adsorption to soybean roots by SBL pretreatment were higher. The last effect was evident only in cultures that had not entered stationary phase. We also studied nodC gene induction in relation to N starvation. In the chromosomal nodC::lacZ fusion Bj110-573, nodC gene expression was induced by genistein 2.7-fold more in N-starved young cultures than in nonstarved ones. In stationary-phase cultures, nodC gene expression was similarly induced in N-limited cultures, but induction was negligible in cultures limited by another nutrient. Nodulation profiles obtained with strain LP 3001 grown under N starvation indicated that these cultures nodulated faster. In addition, as culture age increased, the nodulation efficiency decreased for two reasons: fewer nodules were formed, and nodulation was delayed. However, their relative importance was different according to the nutrient condition: in older cultures the overall decrease in the number of nodules was the main effect in N-starved cultures, whereas a delay in nodulation was more responsible for a loss in efficiency of N-sufficient cultures. Competition for nodulation was studied with young cultures of two wild-type strains differing only in their antibiotic resistance, the N-starved cultures being the most competitive.

Matrix Metalloproteinase 2 (MMP2) and MMP9 Are Produced by Kidney Collecting Duct Principal Cells but Are Differentially Regulated by SV40 Large-T, Arginine Vasopressin, and Epidermal Growth Factor

We analyzed the expression and regulation of matrix metalloproteinase 2 (MMP2) and MMP9 gelatinases in a rabbit kidney collecting duct principal cell line (RC.SVtsA58) (Prié, D., Ronco, P. M., Baudouin, B., Géniteau-Legendre, M., Antoine, M., Piedagnel, R., Estrade, S., Lelongt, B., Verroust, P. J., Cassingéna, R., and Vandewalle, A. (1991) J. Cell Biol. 113, 951-962) infected with the temperature-sensitive (ts) SV40 strain tsA58. At the permissive temperature (33 degreesC), cells produced only MMP2. Shifting cells to a nonpermissive temperature (39.5 degreesC) induced a marked increase in total gelatinolytic activity due to an increase of MMP2 and an induction of MMP9 synthesis. This effect was attributed to large-T inactivation at 39.5 degreesC because it was abolished by re-infecting the cells with wild-type SV40 strain LP. Run-on experiments showed that negative regulation of MMP2 and MMP9 by large-T was transcriptional and posttranscriptional, respectively. MMP2 and MMP9 were also produced by primary cultures of collecting duct cells. In rabbit kidney, both MMP2 and MMP9 were almost exclusively expressed in collecting duct cells, where an unexpected apical localization was observed. Arginine vasopressin and epidermal growth factor, which exert opposite hydroosmotic effects in the collecting duct, also exhibited contrasted effects on MMP9 synthesis. Epidermal growth factor increased but arginine vasopressin suppressed MMP9 at a posttranscriptional level, whereas MMP2 was not affected. These results suggest a specific physiological role of MMP2 and MMP9 in principal cells of renal collecting duct.

Characterization of lactobacilli by Southern-type hybridization with a Lactobacillus plantarum pyrDFE probe.

Lactobacillus plantarum, Lactobacillus pentosus, and Lactobacillus paraplantarum (M.-C. Curk, J.-C. Hubert, and F. Bringel, Int. J. Syst. Bacteriol. 46:595-598, 1996) can hardly be distinguished on the basis of their phenotypes. Unlike L. plantarum and L. paraplantarum, L. pentosus ferments glycerol and xylose but not melezitose. We identified two L. pentosus strains (CNRZ 1538 and CNRZ 1544) which ferment glycerol and melezitose but not xylose. alpha-Methyl-D-mannoside was fermented by 66% of the L. plantarum strains tested but not by L. paraplantarum strains. In this paper we describe a simple method to identify L. plantarum, L. pentosus, and L. paraplantarum. This method is based on nonradioactive Southern-type hybridization between BglI DNA digests of the lactobacilli tested and a DNA probe (L. plantarum pyrDFE genes from strain CCM 1904). A total of 68 lactobacilli were classified into five groups on the basis of the bands detected. Two groups contained L. plantarum strains; one of these groups contained 31 strains, including the type strain, and was characterized by bands at 7, 4, and 1 kb, and the other group contained strain LP 85-2 and was characterized by bands at 5 and 1.1 kb. Only one band (a band at around 7 kb) was detected in the strains belonging to the L. pentosus group, and two bands (at 4 and 1 kb) were found in the strains belonging to the L. paraplantarum group. No hybridization was detected in the last group, which contained Lactobacillus casei, Lactobacillus coryniformis, Lactobacillus paracasei, Lactobacillus brevis, Lactobacillus delbrueckii, and Lactobacillus leichmannii strains.

Interaction of EDTA and Iron on the Accumulation of Cd 2+ in Duckweeds (Lemnaceae)

The influence of free and total concentrations of Cd 2+ in the presence and absence of EDTA on the accumulation in Spirodela polyrhiza (L.) Schleiden, strain SP 20 , and Lemna aequinoctialis Welwitsch, strain LP 6 , was investigated. Accumulation by both plant species correlated with the concentration of free Cd 2+ rather than with total concentration. However, when the ion was removed by the plants from the solution, the EDTA-Cd 2+ complex provided additional free Cd 2+ and accumulation was higher than expected from the calculated free Cd 2+ pool. Because of the high complex stability constant of Fe III -EDTA, Fe 3+ competed with Cd 2+ for EDTA in the solution and, thus, cadmium accumulation was increased by the presence of Fe 3+ . Only after reduction of Fe 3+ to Fe 2+ (low complex stability) or iron uptake by the plants, could the additional EDTA complex Cd 2+ in solution and inhibit its accumulation.

Cloning, nucleotide sequence and expression in Escherichia coli of a gene (ompM) encoding a 25 kDa major outer-membrane protein (MOMP) of legionella pneumophila.

A genomic library derived from a virulent isolate of Legionella pneumophila was constructed in Escherichia coli JM 83 using the cloning vector pUC19. The clones were screened by filter immunoassay using L. pneumophila rabbit polyclonal antisera and in the absence of in situ bacterial lysis one such clone, LP 116, expressed L. pneumophila-specific antigens on the surface of E. coli. Restriction endonuclease digest analysis and agarose gel electrophoresis revealed a fragment measuring approximately 750 bp. Southern hybridization confirmed that the fragment was L. pneumophila DNA. Sequencing data showed that the fragment was 810 bp in length with an open reading frame (ORF) of 678 bp. The outer-membrane profiles of the E. coli parent, the L. pneumophila DNA-contributing strain and clone LP 116 were compared by SDS-PAGE. A protein of 25 kDa was found in outer-membrane preparations of both the clone LP 116 and L. pneumophila but not in E. coli JM 83. This was in agreement with the molecular mass of the deduced peptide of the mature protein. Immunoblots using L. pneumophila-specific polyclonal antiserum confirmed that this 25 kDa outer-membrane protein (OMP) was a L. pneumophila polypeptide. Both direct immunofluorescence assay and immunoblots using the commercially produced monoclonal antibody specific for the common antigen of the major outer-membrane protein (MOMP) confirmed that the 25 kDa protein produced by LP 116 was involved with the MOMP complex. The gene encoding this protein has been designated ompM.(ABSTRACT TRUNCATED AT 250 WORDS)

Mycoplasma simbae sp. nov., Mycoplasma leopharyngis sp. nov., and Mycoplasma leocaptivus sp. nov., isolated from lions.

Mycoplasmas isolated from the throats of lions were shown to belong to three serotypes, all of which were serologically distinct from the previously recognized Mycoplasma and Acholeplasma spp. Eight mycoplasma colonies were cloned, including one from a leopard (strain LP), and were examined in detail for morphology, growth, and biochemical characteristics. The strains had the following properties: guanine-plus-cytosine contents of 37 mol% (strain LXT [T = type strain]), 28 mol% (strain LL2T), and 27 mol% (strain 3L2T) and a requirement for sterol. Strain 3L2T metabolized glucose, which was not metabolized by strains LXT and LL2T. Arginine and urea were not hydrolyzed. Strain LX (= NCTC 11724) is the type strain of a new species, Mycoplasma simbae; strain LL2 (= NCTC 11725) is the type strain of a second new species, Mycoplasma leopharyngis; and strain 3L2 (= NCTC 11726) is the type strain of a third new species, Mycoplasma leocaptivus.

Effect of selected phenolic compounds on the membrane-bound adenosine triphosphatase of Staphylococcus aureus

The effect of selected phenolic compounds on the membrane-bound ATPase activity of two strains of Staphylococcus aureus was studied. These phenolic compounds were: butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), tertiary butylhydroquinone (TBHQ), propyl gallate (PG), p-coumaric, ferulic, caffeic acids, methyl paraben and propyl paraben. Cytoplasmic membrane-bound ATPase activity was measured in the presence of 0, 150, 300, 600 and 1200 μg ml −1 of each phenolic compound. Among all the compounds studied, only BHA was found to significantly stimulate the activity of the enzyme. In contrast, some of the compounds were found to significantly inhibit the activity of the enzyme as was the case of TBHQ, PG, p-coumaric acid, ferulic acid and caffeic acid. The remaining compounds did not influence the activity of the ATPase at any of the concentrations tested. Strain LP ATPase as stimulated less by BHA and inhibited to a greater extent by TBHQ and PG than was the enzyme from strain A100. In contrast, LP ATPase was less inhibited by p-coumaric acid and not affected by either ferulic or caffeic acid.

Clones of MRC-C cells may be superior to the parent line for the culture of 229E-like strains of human respiratory coronavirus

A clone was selected from the MRC-C continuous heteroploid cell line which was significantly better than MRC-C for the culture of human respiratory coronavirus (HCV) 229E, strain LP. Such clones could prove generally useful for the isolation of HCV-229E from clinical specimens, and for the propagation and assay of laboratory adapted strains.

Induction of flowering in Lemna paucicostata by salicylic acid

The duckweed, Lemna paucicostata 6746, is a short-day plant and is known to remain vegetative under long-day conditions in nutrient solutions containing EDTA. Lemna paucicostata, strain LP 6, is a new strain in which so far it has not been possible to induce flowering in vitro either under SD or LD conditions. Here the induction of flowering is reported in both plants under otherwise non-inductive conditions by the use of salicylic acid, a phenol. Aspirin (acetylsalicylic acid) also brings about a similar effect. Flowering in Lemna paucicostata 6746 can be induced to the extent of 60% which is in contrast to an earlier report [1]. The effects of salicylic acid and aspirin on L. paucicostata LP 6 are even more striking since almost 90–100% plants could be induced to flower.

Isoantibodies specific for myeloma γG and γH immunoglobulins of BALB/c mice

Strain LP mice immunized with BALB/c γG myeloma immunoglobulins made precipitating antibodies that identified allotypic specificities common to all BALB/c γG immunoglobulins which were located on the papain Fc fragments, and also identified unique specificities found only on the immunizing myeloma protein.