scholarly journals BIOLOGICAL CONTROL OF FUSARIUM WILT OF CUCUMBER (Cucumis sativus) BY ANTAGONISTIC LACTIC ACID BACTERIA ISOLATED FROM RHIZOSPHERE OF FIVE MEDICINAL PLANTS

2020 ◽  
Vol 18 (1) ◽  
pp. 103-112
Author(s):  
R. A. OLOYEDE ◽  
A. A. ILUPEJU ◽  
O. O. OYELAKIN ◽  
W. R. AJIJOLA
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Medicinal Plants ◽  
Fusarium Wilt ◽  
Disease Incidence ◽  
Culture Method ◽  
Disease Suppression ◽  
Rrna Gene ◽  
Dual Culture

Fusarium wilt is one of the important diseases of cucumber and causes economic loss to farmers. The present study was undertaken to evaluate the potential of rhizosphere lactic acid bacteria as biocontrol agents of Fusarium wilt of cucumber. Lactic acid bacteria (LAB) were isolated and identified from the rhizosphere of five medicinal plants. The in-vitro antagonistic activity of LAB strains on F. oxysporum f.sp. cucumerinum was evaluated by dual culture method. The screen house experiment was then conducted to assess the effect of antagonistic LAB isolates on Fusarium wilt disease incidence in cucumber plants. The antagonistic LAB strains were further characterized using 16S rRNA gene sequencing technique. The total LAB counts of rhizospheric soil samples ranged from 7.0×105 cfu/g to 15.0×105 cfu/g. The LAB isolates were identified as strains of Lactobacillus acidophilus (21.4%), L. plantarum (35.7%), L. fermentum (28.6%), L. alimentarius (7.1%) and L. brevis (7.1%). Treatment of cucumber seeds with antagonistic LAB strains significantly reduced Fusarium wilt of cucumber incidence from 95% to 48%. Lactobacillus fermentum isolated from the rhizosphere of A. indica exhibited strong disease suppression (49.5%). The study therefore revealed that the rhizospheric-LAB could be applied to reduce the manifestation of Fusarium wilt in cucumber.    

scholarly journals Functional Properties and Sustainability Improvement of Sourdough Bread by Lactic Acid Bacteria

2020 ◽  
Vol 8 (12) ◽  
pp. 1895
Author(s):  
Vera Fraberger ◽  
Claudia Ammer ◽  
Konrad J. Domig
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Functional Properties ◽  
Food Additives ◽  
Dual Culture ◽  
Bakery Products ◽  
Gaba Production ◽  
Sourdough Bread ◽  
Increasing Demand

Preventing food spoilage without the addition of chemical food additives, while increasing functional properties of wheat-based bakery products, is an increasing demand by the consumers and a challenge for the food industry. Within this study, lactic acid bacteria (LAB) isolated from sourdough were screened in vitro for the ability to utilize the typical wheat carbohydrates, for their antimicrobial and functional properties. The dual culture overlay assay revealed varying levels of inhibition against the examined fungi, with Lactiplantibacillus plantarum S4.2 and Lentilactobacillusparabuchneri S2.9 exhibiting the highest suppression against the indicator strains Fusarium graminearum MUCL43764, Aspergillus fumigatus, A. flavus MUCL11945, A. brasiliensis DSM1988, and Penicillium roqueforti DSM1079. Furthermore, the antifungal activity was shown to be attributed mainly to the activity of acids produced by LAB. The antibacillus activity was evaluated by the spot-on-the-lawn method revealing a high inhibition potential of the majority of LAB isolated from sourdough against Bacillus cereus DSM31, B. licheniformis DSM13, B. subtilis LMG7135, and B. subtilis S15.20. Furthermore, evaluating the presence of the glutamate decarboxylase gen in LAB isolates by means of PCR showed a strain dependency of a potential GABA production. Finally, due to improved functional activities, LAB isolated from sourdoughs exhibit promising characteristics for the application as natural preservatives in wheat-based bakery products.

Identification and characterisation of the predominant lactic acid-producing and lactic acid-utilising bacteria in the foregut of the feral camel (Camelus dromedarius) in Australia

2011 ◽  
Vol 51 (7) ◽  
pp. 597 ◽  
Author(s):  
M. B. Ghali ◽  
P. T. Scott ◽  
G. A. Alhadrami ◽  
R. A. M. Al Jassim
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Volatile Fatty Acids ◽  
Camelus Dromedarius ◽  
Rrna Gene ◽  
Acid Media ◽  
Butyrivibrio Fibrisolvens ◽  
Prevotella Ruminicola ◽  
De Man

The camel is emerging as a new and important animal in the Australian livestock industry. However, little is known regarding the microbial ecosystem of the gastrointestinal tract of this ruminant-like animal. This study was carried out to determine the diversity of lactic acid-producing and lactic acid-utilising bacteria in the foregut of the feral camel (Camelus dromedarius) in Australia. Putative lactic acid bacteria were isolated from the foregut contents of camels by culturing on De Man, Rogosa, Sharpe and lactic acid media. Identification of representative isolates was based on the analysis of 16S rRNA gene sequences. Fermentation end products of glucose (i.e. volatile fatty acids and lactate) were also measured in vitro. The key predominant bacteria identified in this study were closely related to Streptococcus bovis, Selenomonas ruminantium, Butyrivibrio fibrisolvens, Lachnospira pectinoschiza and Prevotella ruminicola. The main L-lactate producers were those isolates closely related to S. bovis, S. ruminantium and Lactococcus garvieae, while the efficient lactate utilisers were S. ruminantium-related isolates. D-lactate was produced by isolates closely related to either L. pectinoschiza or S. ruminantium. The predominant bacteria isolated and characterised in this study are identical and/or closely related to those typically found in true ruminants (e.g. S. ruminantium, B. fibrisolvens, S. bovis). In addition, some of the bacteria isolated represent novel species of Lachnospira and Clostridium in the context of lactic acid bacteria from a large herbivorous host. The results from this study have contributed to our understanding and provide opportunities to reduce foregut acidosis in the camel.

scholarly journals Diversity and characterization of lactic acid bacteria from Common Carp (Cyprinus carpio L.) intestine in winter (Northern Kazakhstan)

2020 ◽  
pp. 34-47
Author(s):  
Maira Urazova ◽  
◽  
Kunsulu Zakarya ◽  
Zinigul Sarmurzina ◽  
Gulmira Bissenova ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Common Carp ◽  
Universal Primers ◽  
Rrna Gene ◽  
Fish Farms ◽  
Commercial Fish ◽  
Freshwater Aquaculture

Currently, in Kazakhstan, chemical agents and antibiotics are widely used for treatment and prevention of fish diseases at fish farms. The use of probiotics as an alternative to antibiotics can help reduce the spread of antibiotic resistance in this area. The aim of the present study was to isolate the intestinal lactic acid bacteria of wintering carps. We assume that such bacteria can have more adaptive properties and can be used as probiotics for growing carp juveniles at fish farms. A probiotic characteristic of 22 lactic acid bacteria isolated from Common carp intestines was studied. Universal primers were used to determine the sequence of 16S rRNA gene fragments of lactic acid bacteria (LAB). Phylogenetic relationships of the isolates were estimated using the neighbor-joining (NJ) method in Mega 6,0. All identified isolates can grow in temperature range from 10° C to 37° C and in presence of bile salt. The isolated bacteria were screened for antibacterial activity, resistance to bile, resistance to antibiotics and growth at low temperatures. All isolates were tested in vitro for their ability to inhibit the growth of Shewanella xiamenensis, Pseudomonas taiwanensis, Ps. aeruginosa and Aeromonas punctata. As a result, 7 isolates with strong antagonistic activity were selected. 16S rDNA gene sequencing identified 4 isolates as Lactobacillus fermentum, 2 - as L. casei/paracasei and 1 - as Pediococcus pentosaceus. Antibiotic resistance profile of selected strains was studied, too. This study is the first attempt for Kazakhstan to isolate and study the representatives of the normal intestinal microflora of commercial fish species. Selective strains could be potential probiotics for freshwater aquaculture practices in Kazakhstan.

scholarly journals Evaluation of the probiotic and postbiotic potential of lactic acid bacteria from artisanal dairy products against pathogens

2021 ◽  
Vol 15 (01) ◽  
pp. 102-112
Author(s):  
Nazar Hussain ◽  
Muhammad Tariq ◽  
Per Erik Joakim Saris ◽  
Arsalan Zaidi
Keyword(s):  
Antibacterial Activity ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Pathogenic Bacteria ◽  
16S Rrna Gene Sequencing ◽  
Lactobacillus Delbrueckii ◽  
Human Consumption ◽  
Rrna Gene ◽  
Microdilution Method

Introduction: Probiotic and postbiotic potential of thirty-two strains of lactic acid bacteria (LAB), obtained earlier from artisanal dairy sources in Pakistan, have been investigated against major multi-drug resistant (MDR) and food borne pathogenic bacteria. Methodology: LAB strains were identified by 16S rRNA gene sequencing and their antibacterial activity was assessed by the microdilution method. Four LAB isolates, Weissella confusa PL6, Enterococcus faecium PL7, and Lactobacillus delbrueckii PL11 and PL13 were shortlisted. Their ability to degrade lactose and safety for human consumption in terms of hemolysis and antibiotic susceptibility were assessed in vitro. The antibacterial components in the cell-free supernatants (CFSs) of isolate cultures were characterized biochemically by HPLC. Results: Acid neutralization but not protease treatment abolished the antibacterial activity of CFSs. Lactic, acetic and propionic acids were the main acids in the CFSs, and acid production peaked in the stationary phase of growth. The antibacterial activity of the LAB cultures resulted from secretion of organic acids that lowered the pH. The strains exhibited variable ability to degrade lactose and were non-hemolytic and susceptible to the most common antibiotics. Conclusions: These LAB strains are probiotic candidates for further investigation of their postbiotic role in naturally preserving processed foods and for attenuation of lactose intolerance.

scholarly journals In vitro evaluation of lactic acid bacteria with probiotic activity isolated from local pickled leaf mustard from Wuwei in Anhui as substitutes for chemical synthetic additives

2021 ◽  
Vol 19 (1) ◽  
pp. 755-771
Author(s):  
Changjun Wu ◽  
Xiaopei Lin ◽  
Lin Tong ◽  
Chenwei Dai ◽  
Han Lv ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Animal Experiments ◽  
Rrna Gene ◽  
Intestinal Microbes ◽  
Potential Resource ◽  
The 16S Rrna Gene ◽  
Ht 29

Abstract The extensive abuse of chemical synthetic additives has raised increased attention to food safety. As substitutes, probiotics play an important role in human health as they balance the intestinal microbes in host. This study was aimed to isolate and evaluate the potential probiotic activities of lactic acid bacteria (LAB) from a local pickled leaf mustard (PLM) from Wuwei city in Anhui province through in vitro experiments. A total of 17 LAB strains were obtained as probiotics. All the isolates were sensitive to chloramphenicol, tetracycline, erythromycin, and doxycycline but exhibited resistance to antibiotics (e.g., streptomycin, kanamycin, gentamicin, and vancomycin). Out of the 17 strains, 9 were sensitive to most of the antibiotics and had no cytotoxic activity on human colorectal adenocarcinoma cell line (HT-29) cells. The isolated AWP4 exhibited antibacterial activity against four indicator pathogen strains (ATCC8099: Escherichia coli, ATCC6538: Staphylococcus aureus, ATCC9120: Salmonella enteric, and BNCC192105: Shigella sonnei). Based on the phylogenetic analysis of the 16S rRNA gene, AWP4 belonged to Lactiplantibacillus plantarum. This study indicated that the Wuwei local PLM could be a potential resource to isolate beneficial LAB as probiotics. The data provide theoretical guidance for further animal experiments to estimate the probiotic effect and safety of Lpb. plantarum AWP4 in vivo.

scholarly journals Identification and characterization of Pseudomonas fluorescensstrains effective against Xanthomonasoryzaepv. oryzae causing bacterial blight of rice in Punjab, India

2017 ◽  
Vol 9 (1) ◽  
pp. 253-261
Author(s):  
Mandeep Singh Hunjan ◽  
Anjali Thakur ◽  
Pushpinder Paul Singh
Keyword(s):  
Bacterial Blight ◽  
Effective Strain ◽  
Its Region ◽  
Culture Method ◽  
Field Evaluation ◽  
Disease Suppression ◽  
Dual Culture ◽  
Strain Number ◽  
Bacterial Blight Of Rice

For the control of bacterial blight of rice caused by Xanthomonasoryzaepv. oryzae, sixty four Pseudomonas fluorescens strains were recovered from rice and wheat rhizosphere. These strains were identified on the basis of internal transcribed spacer (ITS) region. It was observed that the strains showing fluorescence in the selective media showed the amplification of the targeted P. fluorescens specific ITS region. The strains were also characterized for the production of the antibiotic 2, 4-diacetylphloroglucinol (DAPG) using phlDlocus. The characteristic 750bp region was amplified in all the DAPG producing strains. These strains were evaluated against X. oryzae in vitro by dual culture method. The P. fluorescens strains found effective in vitro were further tested in field for their antagonistic potentiality and disease suppression ability. P. fluorescens strain number Pf-4-R showed maximum inhibition i.e. of 5.5 mm against the test pathogen X. oryzaepv. oryzae. Talc based powder formulation of the effective strain Pf-4-R used for field evaluation, showed that pre-inoculation foliar sprays were effective in controlling bacterial blight of rice with disease suppression efficiency ranging from 29.6 to 65.6 percent in different treatments.

scholarly journals Screening of Bacteriocinogenic Lactic Acid Bacteria and Their Characterization as Potential Probiotics

2020 ◽  
Vol 8 (3) ◽  
pp. 393 ◽  
Author(s):  
Ana Pinto ◽  
Joana Barbosa ◽  
Helena Albano ◽  
Joana Isidro ◽  
Paula Teixeira
Keyword(s):  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Foodborne Pathogens ◽  
Food Products ◽  
In Vivo Studies ◽  
Rrna Gene ◽  
Gene Sequence Analysis

Probiotics are living microorganisms used as nutritional additives that confer health benefits on the host. Their use in food products is very attractive, especially if they could also inhibit important foodborne pathogens. In this study, antimicrobial activity against several foodborne pathogens was screened for 280 lactic acid bacteria (LAB) isolated from different food products and the probiotic characteristics of bacteriocinogenic isolates were evaluated. Seven out of 280 LAB isolates were selected due to their bacteriocinogenic properties and identified by 16S rRNA gene sequence analysis as Pediococcus pentosaceus (n = 6) and Lactobacillus plantarum (n = 1). Virulence factors and antibiotic resistances were not detected for any of the isolates. Except for L. plantarum R23, all the isolates were able to survive through the simulated gastrointestinal tract conditions. Only P. pentosaceus CFF4 was able to adhere to Caco-2 cells after the simulated gastrointestinal tract passage. In conclusion, even though in vivo studies should be performed, P. pentosaceus CFF4, which was also able to inhibit the growth of foodborne pathogens in vitro, seems to be a potential probiotic to be used in the food industry.

scholarly journals Evaluation of Streptomyces spp. against Fusarium oxysporum f. sp. ciceris for the management of chickpea wilt

2016 ◽  
Vol 56 (3) ◽  
pp. 257-264 ◽  
Author(s):  
Jahanshir Amini ◽  
Zahra Agapoor ◽  
Morahem Ashengroph
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Mycelial Growth ◽  
Biochemical Characterization ◽  
Culture Method ◽  
Biocontrol Agents ◽  
Dual Culture ◽  
Bacterial Strains ◽  
Chickpea Wilt

AbstractIn this study, about 112 isolates ofStreptomyceswere isolated from chickpea rhizospheric soils. Among the isolated strains, five showed strong inhibitory effects against chickpea Fusarium wilt caused byFusarium oxysporumf. sp.ciceris in vitrousing plate assay and selected for further studies. The selected strains were identified asStreptomycesspp. based on morphological and biochemical characterization as well as 16S rDNA sequences analysis. Our results assigned them to strains related to genus ofStreptomyces.In vitro, antagonistic effects ofStreptomycesstrains against the disease were evaluated through the dual-culture method, volatile and non-volatile metabolites, siderophore, protease and chitinase production. All bacterial strains inhibited mycelial growth of the pathogen ranging from 26 to 44.2% in dual culture assay. The non-volatile extract of five of theStreptomycesstrains inhibited more than 50% growth of the pathogen, whereas volatile compounds were less effective on mycelial growth inhibition (20.2 to 33.4%). The ability of the biocontrol agents to produce siderophore and protease were varied, whereas, production of chitinase was detected for all strains. Results of the greenhouse assay indicated that all biocontrol agents reduced disease severity (ranging from 38.7 to 54.8%). Accordingly, strain KS62 showed higher control efficacy (54.8%). In addition, the biomass of chickpea plants (plant height and dry weight) significantly increased in plants treated withStreptomycesstrains compared to non-bacterized control. The results of this study showed that it may be possible to manage chickpea Fusarium wilt disease effectively by usingStreptomycesspecies, as biocontrol agents. Therefore, evaluating their efficiency under field conditions is needed.

Construing the Role of Plant Extracts, Fungicides and Bio-agents in Ameliorating Fusarium Wilt Management in Chickpea

2021 ◽  
Author(s):  
Annie Khanna ◽  
Kushal Raj ◽  
Pankaj Kumar
Keyword(s):  
Fusarium Oxysporum ◽  
Fusarium Wilt ◽  
Seed Yield ◽  
Plant Extracts ◽  
Seed Treatment ◽  
Disease Incidence ◽  
Field Conditions ◽  
Dual Culture ◽  
Chickpea Wilt

Background: Chickpea (Cicer arietinum L.) is the most important leguminous crop around the world. Fusarium wilt incited by Fusarium oxysporum f. sp. ciceris is a major biotic constraint in chickpea production. The present investigation was undertaken to evaluate the efficacy of plant extracts, fungicides and bio-agents against Fusarium oxysporum f. sp. ciceris under in vitro and field conditions. Methods: Plant extracts and fungicides were evaluated using poison food technique while antagonistic activity of bio-agents was studied using dual culture technique under in vitro conditions. Field trials were conducted to evaluate the efficacy of different plant extracts, fungicides and bio-agents against Fusarium wilt at Experimental Area of Plant Pathology, CCS HAU, Hisar.Result: Among thirteen plant extracts evaluated in vitro, neem leaves extract was found to be the most effective in inhibiting mycelial growth of F. oxysporum f. sp. ciceris followed by datura leaves’ and garlic cloves’ extract which were statistically at par. Out of six plant extracts tested against Fusarium wilt under field conditions, seed treatment with extracts of neem and datura leaves at 10% concentration were most effective and curtailed the wilt incidence by 39.02 and 34.14% along with 7.55 and 6.83% enhanced seed yield. Among fungicides, carbendazim 50 WP was the most toxic fungicide in restricting colony diameter of the pathogen with the least EC50 and EC90 values of 1.28 and 15.24 ppm a.i. followed by azoxystrobin 23 SC with corresponding values of 1.57 and 49.16 ppm a.i., respectively. Seed treatment with carbendazim 50 WP and azoxystrobin 23 SC were superior over other treatments and provided 88.41 and 85.98% reduction in disease incidence along with 12.85 and 10.99% higher seed yield over control. Among the bio-agents tested, T. viride and T. harzianum gave the best results in suppressing the pathogen growth in vitro and in minimizing the disease incidence coupled with improvement in seed yield under field conditions. The present study has provided chemical and non-chemical measures for integrated management of chickpea wilt.

scholarly journals Characterization of Lactic Acid Bacteria Isolated from the Gastrointestinal Tract of Ethiopian Rhode Island Red Chicken and their Potential Use as Probiotics

2019 ◽  
Author(s):  
Kibrnesh Tegenaw Tsega ◽  
Kagira Maina ◽  
Nega Berhane
Keyword(s):  
Lactic Acid ◽  
Gastrointestinal Tract ◽  
Lactic Acid Bacteria ◽  
Rhode Island ◽  
Gene Sequence ◽  
Cell Surface Hydrophobicity ◽  
Feed Additives ◽  
Good Survival ◽  
Rrna Gene

Abstract Background Chicken productivity and survival is affected by environmental stress and incidences of different diseases. After the ban of antibiotics growth promoters by different countries, the use of probiotics feed additives is mentioned as one alternative to antibiotics. The objective of this study was to isolate and identify potential probiotic lactic acid bacteria strains from the digestive tract content of Rhode Island Red chicken. Results The study was conducted in Gondar town of Amhara region, North West Ethiopia from November, 2018 to March, 2019. From the gastro intestinal content of 5 chicken 190 isolates were randomly selected. The isolates were identified and screened by their biochemical, morphological and 16S rRNA gene sequence. The in vitro probiotic potential of isolates was characterized by various tests. From 190 isolates 73 were found as gram positive, catalase negative and were able to grow at pH4. The bacteria were either rod (83.6%) or round (16.4%) shaped. Ten isolates were then randomly selected for further in vitro probiotic characterization due to higher cell surface hydrophobicity, good survival at pH2 and survival at 0.1% bile salt. From the 10 isolates 6 were able to survive at pH1 for 3hrs incubation. Five isolates (IS1, IS2, IS5, IS7 and IS8) were resistance to ampicillin, chloramphenicol, ciprofloxacin and erythromycin antibiotics. All the ten isolates showed antagonistic activity against Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Staphylococcus intermedius and Salmonella enteritidis. The optimum temperature for all ten isolates was 450C and all the isolates were able to grow at 0.69 mol/L of NaCl, and were able to ferment galactose, glucose, fructose, mannitol, sorbitol and sucrose. Using phylogenetic analysis of 16SrRNA gene sequence; IS3 was identified as Lactobacillus salivarius while IS4, IS6 and IS7 were identified as Lactobacillus reuteri. Conclusion The study concludes that the 10 selected isolates can be able to survive the stress conditions of gastrointestinal tract and can thus be considered as potential probiotics candidates for chickens.

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