Antibacterial Activity and Mechanisms of Ethanol Extracts from Scutellaria baicalensis Georgi and Magnolia officinalis against Phytophthora nicotianae

Phytophthora nicotianae causes substantial economic losses in most countries where tobacco is produced.At present,the control of P.nicotianae mainly depends on chemical methods,with considerable environmental and health issues.We investigated the effects of ethanol extracts from Scutellaria baicalensis Georgi(SBG)and Magnolia officinalis(MO).On mycelial growth,sporangium formation,and zoospore release of P.nicotianae.Both extracts inhibited the growth of P.nicotianae,with mycelial growth inhibition rates of 88.92%and 93.92%,respectively,at 40 mg/mL,and EC50 values of 5.39 and 5.74 mg/mL,respectively.The underlying mechanisms were the inhibition of sporangium formation,the reduction of zoospore number,and the destruction of the mycelium structure.At an SBG extract concentration of 16.17 mg/mL,the inhibition rates for sporangia and zoospores were 98.66%and 99.39%,respectively.At an MO extract concentration of 2.87 mg/mL,the production of sporangia and zoospores was completely inhibited.The hyphae treated with the two plant extracts showed different degrees of deformation and damage.Hyphae treated with SBG extract showed adhesion and local swelling,whereas treatment with MO extract resulted in broken hyphae.Mixture of the extracts resulted in a good synergistic effect.

Phytochemicals, polyphenols content, in vitro antioxidant and antibacterial activities of Albizia coriaria Welw ex. Oliver flowers

Albizia coriaria Welw ex.Oliver(hereafter A.coriaria)is a revered medicinal tree whose organs are used by indigenous African societies for managing various ailments.Herein,we assessed the secondary metabolites,total polyphenolics,free radical scavenging and antimicrobial activities of A.coriaria flowers.The dry powdered sample was extracted serially with ethyl acetate,ethanol and distilled water.Results of classical phytochemical screening showed that saponins,phenols,alkaloids,flavonoids,tannins and terpenes were the dominant phytochemicals.The highest total polyphenolic content(10.37±0.02 mg QE/g DW and 72.09±0.09 mg GAE/g DW)and free radical scavenging potential(IC50=24.23±0.04 mg/mL)were for the ethyl acetate extract.It also had a higher bacteriostatic activity than the ethanolic extract against Pseudomonas aeruginosa,Salmonella typhi,Escherichia coli and Staphylococcus aureus with diameters of inhibition ranging from 7.00±0.00 to 22.00±1.73 mm.The aqueous extract showed no appreciable antibacterial effect on the tested microorganisms.This is the first report which support the use of floral extracts of this species in the management of ailments in African traditional medicine.

Study on Bacteriostatic Properties of Piroctone Olamine in Commonly Used Surfactants Systems

Piroctone olamine(OCT) was used as the main bacteriostatic component, the inhibition of OCT in different kinds and mass concentrations of surfactants were studied. Six surfactants commonly used in personal care products, i.e. sodium laureth sulfate(AES), cocamidopropyl betaine(CAB 35), sodium lauroyl sarcosinate(LS-30), sodium lauroyl glutamate(ULS-30S), alkyl glycoside(APG), cocamide methyl MEA(CMMEA),were used. The results showed that the bacteriostatic of OCT decreased with the increase of AES, which was suggested ≤ 5%. OCT has good bacteriostatic performance in the systems of amino acid surfactants and high dosage of amphoteric surfactants, 5% LS 30 and ≥ 10% CAB 35 was recommended. High dosage of nonionic surfactant could interfere the bacteriostatic performance of OCT, the recommended dosage was ≤ 2%.In addition, OCT has good bacteriostatic performance against Staphylococcus aureus, Escherichia coli and Candida albicans when pH was controlled less than 5.5.

Study on the Bacteriostatic Effects of 7 Kinds of Chinese Herbal Medicines such as Ophiopogon japonicus and Comb

[Objective] The aim was to explore the effects of seven kinds of Chinese herbal medicine on Escherichia coil and Staphylococcus aureus in terms of unilater- al bacteriostatic effect, such as root and leaf of Ophiopogon japonicus, honeycomb, Panax pseudoginseng, and Allium macrostemon. [Method] Herbal active ingredients were extracted by water boiling method and a bacteriostatic experiment was per- formed by oxford cup diffusion method, to select Chinese herbs with antibacterial effects. MIC values of seven kinds of Chinese herbal medicine were determined by in vitro half-fold dilution method. [Results] Root and leaf of Ophiopogon japonicus, honeycomb, Panax pseudoginseng, Allium macrostemon, Juncus effusus and Xanthi- um sibiricum had bacteriostatic effects on Escherichia coil and Staphylococcus au- reus in varying degrees. Xanthium and leaf of Ophiopogon japonicus performed bet- ter on Escherichia coil, with MIC values at 7.81 and 15.63 mg/ml, respectively. Panax pseudoginseng and Xanthium performed better on Staphylococcus aureus with MIC values at 15.63 and 31.25 mg/ml. And the drug＇s effect was positively correlated with the concentration. [Conclusion] Xanthium sibiricum is the best bacte- riostatic effect, followed by leaf of Ophiopogon japonicus, and Juncus effusus per- forms the poorest. Panax pseudoginseng showed the best bacteriostatic effect, fol- lowed by Xanthium sibiricum and Juncus effusus performs the poorest. These pro- vide references for clinic safety.

Antibacterial Effect of Waste Liquor of Essence Oil Extraction from Sabina vulgaris Ant in Foods

The antibacterial effects of waste liquor of essence oil extraction from Sabina vulgaris Ant on Escherichia coil, Staphylococcus aureus, Salmonella, Bacillus subtilis, Bacillus magaterium and Bacillus cereus in foods were evaluated by paper disk method. The results showed that the waste liquor of essence oil extraction from S. vulgaris had inhibitory effects on E. coil, S. aureus and Salmonella with bet- ter inhibitory effects on E. coil and Salmonella; the bacteriostatic effect of water steam distillation waste liquor was better than that of water extraction waste liquor. The more times the waste liquor was distilled, the higher the active ingredients content was, and the better the bacteriostatic effect was.

Effect of Bacteriostat(Qianxing No.1) on Open Tissue Culture of Sugarcane

[Objective] The effect of bacteriostat （Qianxing No.l） on open tissue cul- ture of sugarca6e was discussed in this paper. [Method] The axillary bud explants of Qiantang No.5 were used as experimental material. Different concentrations of Qianxing No.1 were added in the media to determine the optimal bacteriostatic con- centrations of Qianxing No.1 for induction and proliferation culture of sugarcane in the open tissue culture. [Result] The results showed Qianxing No.1 with the con- centration of 0.5% could effectively inhibit the medium contamination. Under that bacteriostatic concentration, the surviving rate of explants was up to 80%, and the propagation coefficient was 3.1. [Conclusion] This research would provide a theoretic basis for the simplification of sugarcane tissue culture procedure and the reduction of production costs.

Sensitivities of Vibrio vulnificus to Chinese Herbs and Effect of Medicinal Bath on Vibrio vulnificus

Vibrio vulnificus can cause rotten-skin disease in marine fish aquaculture, resulting in a large number of deaths. The occurrence of rotten-skin disease is becoming severer and severer, leading to serious economic losses. In this study, the sensitivities of V. vulnificus to the 18 kinds of herbs, such as stone calamus and Chinese rhubarb, were determined using the agar diffusion method （susceptibility paper）. The results showed that Chinese gall, dark plum, sea buckthorn and eucalyptus leaves have bacteriostatic and bactericidal effects, while sappan wood, Chi- nese rhubarb, pomegranate bark, mentha and clove have strong bacteriostatic ef- fects. The Chinese medicinal herb bath showed good control effect on V. vulnificus.

Drug Sensitive Test on Main Pathogenic Bacteria of Cow Recessiveness Mastitis Using Traditional Chinese Medicine Preparation “Zengrujianniusan”

According to the theory of Chinese veterinary medicine and characteristics of Chinese herbal medicine, four different preparations of compound Chinese medicine ＂Zengrujianniusan＂ were composed, and the prepared water decoction was used to carry on the bacteriostatic test on main pathogens of cow recessiveness mastitis. The results showed that the four different prescriptions of water decoction all had antibacterial effects. The prescription 3 was sensitive to Staphylococcus aureus and Streptococcus agalactiae, while the other three prescriptions showed high sensitivity, and the prescription 3 had the strongest bacteriostatic effects.

Preparation of a Novel Highly Effective and Environmental Friendly Wheat Seed Coating Agent

A novel environmental friendly wheat seed coating agent was prepared from the natural polymer,biological pesticide,microfertilizer,microelements and other additives.The laboratory and field test results showed that it could enhance the yield up to 16% and reduce its input cost to 1/6 as compared with the conventional wheat seed coating agent.It is safe without causing any pollution and would have significant economic and environmental benefits.

In Vitro Bacteriostatic Activity of Five Chinese Herbal Medicines against Two Common Pathogens of Scylla serrata

[ Objective] To investigate the in vitro bacteriostatic activity of Chinese herbal medicines （ rhubarb, Baikal skullcap root, honeysuckle, eucommia bark and Chinese date） and their compounds against two common pathogens of Scylla serrata （ Vibrio parahaemolyticus and Aeromonas hydrophila）. [Method] Drug sensitivity of the bacteria was determined by paper method. Minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC） were determined by dilution method and plate method, respectively. [Result] The bacteriostatic order of single medicines on V. parahaemolyticus were Baikal skullcap root 〉 honeysuckle 〉 rhubarb 〉 Chinese date 〉 eucommia bark. The bacteriostatic order of the compounds were A =B = C 〉 D. Among these medicines, the Baikal skullcap root and the compounds A, B, C and D had better bactericidal effects on V. parahaemolyticus. The bacteriostatic order of single medicines on A. hydrophila was rhubarb 〉 Baikal skullcap root 〉 honeysuckle 〉 Chinese date 〉 eucommia bark. The bacteriostatic order of the compounds were A 〉 B 〉 C = D, while the rhubarb and the compound C had better bactericidal effects on A. hydrophila. [ Conclusion] The Chinese herbal medicines including rhubarb, Baikal skullcap root, honeysuckle, eucommia bark and Chinese date have good bacteriostatic effects on V. parahaemolyticus and A. hydrophila, and they can be used to treat bacterial infection in Scylla serrata.

Fungi with potential probiotic properties isolated from Fuzhuan brick tea

Several of the fungal species associated with Fuzhuan brick tea(FBT)are considered as potential probiotics,but few studies have investigated the probiotic properties of these fungi.Here,we isolated 18 fungal strains from two types of FBT and identified these strains based on internal transcribed spacer(ITS)fragment sequence similarity to reference strains(sequence similarity>98%).Of the 18 strains,10 tolerated simulated human digestive conditions for sufficient periods in vitro:pH 2-3,0.3%-0.5%(m/V)bile salts,and artificial gastrointestinal juices.We then measured the antimicrobial activity of the remaining 10 strains against 5 enteropathogenic bacteria and tested the bacteriostatic effects of the thalli and fermentation broth extracts.Of the 6 strains with strong bacteriostatic effects,we eliminated Eurotium cristatum S-9 due to its low hydrophobicity of(26.12±0.35)%.Finally,2 exhibited good adhesion abilities to human cells(>100%).Notably,2 strains can survive in vivo,because they can be isolated from C57BL/6 mice feces.Thus,2 strains,Aspergillus cristatus H-1 and A.cristatus H-5,are herein identified as promising candidate probiotic strains.It may be put forward a novel research focus on evaluating potential probiotic fungi from FBT.

Screening and Identification of Biocontrol Strains against Potato Black Shank Disease,Pectobacterium atrosepticum

[Objective]The paper was to screen and identify biocontrol strains against potato black shank disease in Inner Mongolia.[Method]Totally 58 strains of Bacillus spp.preserved in the laboratory were used to screen and identify biocontrol agents against potato black shank disease,and the antagonistic activities of strains were determined by plate confrontation culture method.[Result]A total of 17 strains showed antagonistic activity against Pectobacterium atrosepticum in potato,accounting for 29.31%of the tested strains.Five strains with better antagonistic effect were obtained by further screening,namely Chi8-7,Genyun4-4,Gen7-4,Jing6-7,and S-7.Genyun4-4 had the most obvious bacteriostatic effect,and the average inhibition zone diameter reached 20.7 mm,significantly higher than those of other tested strains.Results of bioactivity determination also demonstrated that the strain had better bacteriostatic effect.Through morphological observation,molecular identification and physiological and biochemical characteristics determination,the strain Chi8-7 was identified as Bacillus amyloliquefaciens;the strain Genyun4-4 was identified as B.subtilis;and strains Gen7-4,Jing6-7 and S-7 were identified as B.methylotrophicus.[Conclusion]The results will lay a theoretical basis for biological control against potato black shank disease in Inner Mongolia.

Bacteriostatic Effect of Extracts from 10 Kinds of Traditional Chinese Medicinal Materials and Garlic on Pectobacterium chrysanthemi

Pectobacterium chrysanthemi is one of the main pathogens of soft rot disease of Amorphophallus konjac.The bacteriostatic effect of extracts from 10 kinds of traditional Chinese medicine and garlic on Pectobacterium chrysanthemi was studied in this experiment.The results showed that the extracts of Coptis chinensis,garlic,Scutellaria baicalensis,Mume Fructus and Bupleurum had significant bacteriostatic effect.Among them,Coptis chinensis and garlic had the best bacteriostatic effect on Pectobacterium chrysanthemi,and the diameter of inhibition zone was 2.27 and 2.19 cm,respectively,followed by Scutellaria baicalensis,with the diameter of inhibition zone of 1.68 cm.The extracts of Coptis chinensis,Scutellaria baicalensis and garlic with good bacteriostatic effect were diluted by double dilution method,and the bacteriostatic effect was determined.The results showed that 2-fold dilution of Coptis chinensis and 2-fold and 4-fold dilution of Scutellaria baicalensis had significant bacteriostatic effect,but the bacteriostatic effect of garlic extract was not obvious after dilution.

Selection and Molecular Biological Identification of a Strain of Bacillus sp. Inhibiting the Growth of Saprolegnia ferax

Based on the theory of biological control of Saprolegnia ferax,antagonism test of nine strains of Bacillus sp. to S. ferax JL was carried out. Bacillus sp.BA1 was screened to have significantly inhibitory effects on the growth of S. ferax JL( P 【 0. 05). Then,the effects of Bacillus sp. BA1 on different sources of S. ferax were carried out. Results showed that BA1 also had significantly inhibitory effects on S. ferax 6#,10# and S2( P 【 0. 05). Sequence of 16 S r DNA of BA1 was analyzed; and homologous alignment analysis showed that BA1 had more than 99% similarity with Bacillus cereus. Therefore,it could be concluded that strain BA1 was B. cereus,which significantly inhibited the growth of S. ferax and could be used as the biological control agent for S. ferax diseases in aquaculture.

In-vitro Synthesis and Activity Identification of Antimicrobial Peptide from Aspergillus granifolium

[Objectives] This study was conducted to investigate the control effect of antimicrobial peptides to peanut aflatoxin contamination and achieve the purpose of biological control of peanut aflatoxin.[Methods]Bioinformatics methods were applied to screen antimicrobial peptides with strong antifungal activity in the antimicrobial peptide database and analyze their secondary structures and bacteriostatic characteristics,and the candidated peptide was then artificially synthesized,expressed and purified and detected for in-vitro activity.[Results] The antimicrobial peptide(AFP1) which was screened from Aspergillus granifolium exhibited strong antimicrobial activity against Aspergillus flavus.The inhibition rate of crude AFP1 at 3 mg/ml reached 58% for gram-positive bacteria,52% for gram-negative bacteria,and 62% for A.flavus.[Conclusions]This study provides a new approach for the prevention and control of various plant diseases including peanut disease,and a new idea for the biological prevention and control of plant diseases.

Bacteriostatic Effects of Hyaluronan-Based Bioresorbable Membrane

Purpose: The purpose of this study is to determine the presence of bacteriostatic effects of hyaluronan-based bioresorbable membrane (HA/CMC) on selected major bacterial strains in digestive organs. Methods: We firstly evaluated the growth inhibition effect of HA/CMC for E. coli and S. aureus by determining the optical density (OD)650 in the incubation medium. At second, to determine the viable counts of bacteria, total adenosine triphosphate (ATP) were measured with five groups;several concentrations of HA/CMC and control. Results: OD curve gradually elevated and reached to plateau at 4 hours in E. coli. and 6 hours in S. aureus. After reaching plateau, the growth inhibition of both strains was statistically significantly correlated to the concentrations of HA/CMC. The ATP productions had statistically significant differences at 6 hours after incubation and inhibited in dose-dependence of a well-dissolved HA/CMC. Conclusion: HA/CMC may have dose-dependently bacteriostatic effects on S. aureus and E. coli.

Development of a Construction Material for Indoor and Outdoor, Metakaolinite-Based Geopolymer, with Environmental Properties

Environmental problems that came from the human activity have many facets,since pollution of the atmosphere arises from vehicles,industrial emissions while pollution of water could be from organic compounds,pesticides etc.These can cause serious health effects,such as respiratory diseases,including asthma and lung cancer.Hence,in the present work,a kinetic study on the effective adsorption and photo degradation of methylene blue(MB)dye,under ultraviolet A(UVA)irradiation of an alkali activated inorganic polymer(geopolymer)with homogeneously dispersed titanium dioxide(TiO2)micro-particles is presented.In addition,antimicrobial testing of the alkali activated TiO2 material was performed showing a bacteriostatic effect.

Preparation and Quality Evaluation of Salicylic Acid Gel

Taking salicylic acid as the active ingredient and 10%sodium hydroxide aqueous solution as the neutralizer,the best matrix for preparing gel was screened,and the salicylic acid aqueous gel was prepared.The properties,pH value and viscosity were determined,and the stability,antibacterial activity and irritation were evaluated.The experimental results showed that the best gel matrix was cellulose,which had the best stability,could increase the solubility of salicylic acid in gel preparations,solved the problem of easy precipitation of salicylic acid crystals,enhanced the antibacterial activity,and reduced irritation,providing a reference for the application of salicylic acid in cosmetics.

Application of Dodecyl Dimethyl Benzyl Ammonium Chloride in Bacteriostatic Laundry Detergent

Bacteriostatic laundry detergent was prepared with application of dodecyl dimethyl benzyl ammonium chloride (1227). In accordance with relevant standards applied in Chinese detergent industry, the effect of 1227 on sensory and physiochemical quality indices, detergency and foaming performance of laundry detergent were comprehensively investigated,and antimicrobial performance as well as practical application performance including skin irritation of laundry detergent formulated with 1227 was emphatically examined and compared with that of market product with similar functions. Results indicated that, in formulation without anionic surfactant, all indices of self-prepared bacteriostatic laundry detergent can meet requirements specified in relevant standards. The foaming power of self-prepared bacteriostatic laundry detergent was lower and easier to rinse than bacteriostatic laundry detergent product in market. Using aqueous solution of 1% mass fraction of self-prepared bacteriostatic laundry detergent containing 2%of 1227, the antibacterial rate for 20 min on both Escherichia coli and Staphylococcus aureus separately reached 100%, which was much better than that of the bacteriostatic laundry detergent product from market. The action effectiveness of the self-prepared bacteriostatic laundry detergent can be maintained for a longer time period and shows no obvious irritation effect to human skin.