scholarly journals Random compound mutagenesis breeding of Bacillus amyloliquefaciens X030 with high resistance to pathogenic bacteria on grass carp

2021 ◽  
Author(s):  
Pengji Zhou ◽  
Haiyan Huang ◽  
Jiaoyang Lu ◽  
Zirong Zhu ◽  
Junyan Xie ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Grass Carp ◽  
Bacillus Amyloliquefaciens ◽  
Pathogenic Bacteria ◽  
Kidney Tissue ◽  
Gene Clusters ◽  
Original Strain ◽  
Temperature Plasma ◽  
Aeromonas Veronii ◽  
Macrolactin A

Abstract Background: Bacillus amyloliquefaciens X030 (BaX030) was obtained by screening from peanut fields in Henan Province, China. It had broad-spectrum antibacterial activity against fish pathogens Aeromonas hydrophila and Aeromonas veronii. In order to improve its antibacterial effect, BaX030 was carried out the compound mutagenesis that atmospheric and room temperature plasma (ARTP) combined with nitrosoguanidine (NTG). Results: The result showed the yield of macrolactin A and oxydifficidin of the mutant N-11 were increased by 2.01 times and 3.68 times, respectively. Re-sequencing found that the corresponding 9th and 15th gene clusters had 4 and 6 SNP mutations, respectively, the 15th gene cluster also had 7 InDel mutations. Scanning electron microscopy observed that the N-11 became thin and long. The results of qRT-PCR indicated that feeding the N-11 can increase the expression of immune factors in the liver or kidney tissue of grass carp. It can also significantly reduce the mortality and the surface symptoms of grass carp that was infected by two pathogens through HE staining and protection experiments.Conclusion: This is the first report that after ARTP-NTG compound mutagenesis, a high-yielding strain of macrolactin A and oxydifficidin were increased by 2.01 times and 3.68 times compared with the original strain, respectively, which laid the foundation for elucidating its biological regulation, they had antibacterial effects on Aeromonas hydrophila and Aeromonas veronii. We combined re-sequencing to find the mutation sites of gene clusters and. The probiotic strain N-11 can quickly activate the immune protection mechanism of grass carp to resist pathogenic bacteria.

scholarly journals Mannan Oligosaccharides Application: Multipath Restriction From Aeromonas hydrophila Infection in the Skin Barrier of Grass Carp (Ctenopharyngodon idella)

2021 ◽  
Vol 12 ◽  
Author(s):  
Zhiyuan Lu ◽  
Lin Feng ◽  
Wei-Dan Jiang ◽  
Pei Wu ◽  
Yang Liu ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Aeromonas Hydrophila ◽  
Grass Carp ◽  
Barrier Function ◽  
Pathogenic Bacteria ◽  
Skin Barrier ◽  
Ctenopharyngodon Idella ◽  
Skin Barrier Function ◽  
Grass Carp Ctenopharyngodon Idella ◽  
Mannan Oligosaccharides

The objective of this study was to evaluate the efficacy of dietary Mannan oligosaccharides (MOS) supplementation on skin barrier function and the mechanism of on-growing grass carp (Ctenopharyngodon idella). Five hundred forty grass carp were fed for 60 days from the growing stage with six different levels of MOS diets (0, 200, 400, 600, 800, and 1,000 mg kg-1). At the end of the growth trial, the 14-day Aeromonas hydrophila challenge experiment has proceeded. The obtained data indicate that MOS could (1) decline skin lesion morbidity after being challenged by the pathogenic bacteria; (2) maintain physical barrier function via improving antioxidant ability, inhibiting excessive apoptosis, and strengthening the tight junction between the epithelial cell and the related signaling pathway (Nrf2/Keap1, p38MAPK, and MLCK); and (3) regulate immune barrier function by modulating the production of antimicrobial compound and expression of involved cytokines and the related signaling pathway (TOR and NFκB). Finally, we concluded that MOS supplementation reinforced the disease resistance and protected the fish skin barrier function from Aeromonas hydrophila infection.

scholarly journals A transcriptome analysis focusing on inflammation-related genes of grass carp intestines following infection with Aeromonas hydrophila

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Xuehong Song ◽  
Xiaolong Hu ◽  
Bingyao Sun ◽  
Yunxuan Bo ◽  
Kang Wu ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Aeromonas Hydrophila ◽  
Grass Carp

scholarly journals Extract from phyllosphere bacteria with antibiofilm and quorum quenching activity to control several fish pathogenic bacteria

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Olivia Nathalia ◽  
Diana Elizabeth Waturangi
Keyword(s):  
Streptococcus Agalactiae ◽  
Aeromonas Hydrophila ◽  
Biofilm Formation ◽  
Pathogenic Bacteria ◽  
Vibrio Harveyi ◽  
Quorum Quenching ◽  
Indicator Bacteria ◽  
Antibiofilm Activity ◽  
Fish Pathogen ◽  
Phyllosphere Bacteria

Abstract Objective The objective of this research were to screen quorum quenching activity compound from phyllosphere bacteria as well as antibiofilm activity against several fish pathogen bacteria such as Aeromonas hydrophila, Streptococcus agalactiae, and Vibrio harveyi. Results We found eight phyllosphere bacteria isolates with potential quorum quenching activity to inhibit Chromobacterium violaceum as indicator bacteria. Crude extracts (20 mg/mL) showed various antibiofilm activity against fish pathogenic bacteria used in this study. Isolate JB 17B showed the highest activity to inhibit biofilm formation of A. hydrophila and V. harveyi, meanwhile isolate JB 3B showed the highest activity to inhibit biofilm of S. agalactiae. From destruction assay, isolate JB 8F showed the highest activity to disrupt biofilm of A. hydrophila isolate JB 20B showed the highest activity to disrupt biofilm of V. harveyi, isolate JB 17B also showed the highest activity to disrupt biofilm of S. agalactiae.

scholarly journals Overproduction of Ristomycin A by Activation of a Silent Gene Cluster in Amycolatopsis japonicum MG417-CF17

2014 ◽  
Vol 58 (10) ◽  
pp. 6185-6196 ◽  
Author(s):  
Marius Spohn ◽  
Norbert Kirchner ◽  
Andreas Kulik ◽  
Angelika Jochim ◽  
Felix Wolf ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gene Cluster ◽  
High Performance ◽  
Pathogenic Bacteria ◽  
Genome Mining ◽  
Gene Clusters ◽  
Von Willebrand Disease ◽  
Biosynthesis Gene Cluster ◽  
Content Type ◽  
Bioinformatic Tools

ABSTRACTThe emergence of antibiotic-resistant pathogenic bacteria within the last decades is one reason for the urgent need for new antibacterial agents. A strategy to discover new anti-infective compounds is the evaluation of the genetic capacity of secondary metabolite producers and the activation of cryptic gene clusters (genome mining). One genus known for its potential to synthesize medically important products isAmycolatopsis. However,Amycolatopsis japonicumdoes not produce an antibiotic under standard laboratory conditions. In contrast to mostAmycolatopsisstrains,A. japonicumis genetically tractable with different methods. In order to activate a possible silent glycopeptide cluster, we introduced a gene encoding the transcriptional activator of balhimycin biosynthesis, thebbrgene fromAmycolatopsis balhimycina(bbrAba), intoA. japonicum. This resulted in the production of an antibiotically active compound. Following whole-genome sequencing ofA. japonicum, 29 cryptic gene clusters were identified by genome mining. One of these gene clusters is a putative glycopeptide biosynthesis gene cluster. Using bioinformatic tools, ristomycin (syn. ristocetin), a type III glycopeptide, which has antibacterial activity and which is used for the diagnosis of von Willebrand disease and Bernard-Soulier syndrome, was deduced as a possible product of the gene cluster. Chemical analyses by high-performance liquid chromatography and mass spectrometry (HPLC-MS), tandem mass spectrometry (MS/MS), and nuclear magnetic resonance (NMR) spectroscopy confirmed thein silicoprediction that the recombinantA. japonicum/pRM4-bbrAbasynthesizes ristomycin A.

scholarly journals Complete Genome Sequences of Three Bacillus amyloliquefaciens Strains That Inhibit the Growth of Listeria monocytogenes In Vitro

2018 ◽  
Vol 6 (25) ◽  
Author(s):  
Thao D. Tran ◽  
Steven Huynh ◽  
Craig T. Parker ◽  
Robert Hnasko ◽  
Lisa Gorski ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Secondary Metabolites ◽  
Growth Inhibition ◽  
Complete Genome ◽  
Bacillus Amyloliquefaciens ◽  
Gene Clusters ◽  
Genome Sequences ◽  
Multiple Gene ◽  
Content Type

ABSTRACT Here, we report the complete genome sequences of three Bacillus amyloliquefaciens strains isolated from alfalfa, almond drupes, and grapes that inhibited the growth of Listeria monocytogenes strain 2011L-2857 in vitro. We also report multiple gene clusters encoding secondary metabolites that may be responsible for the growth inhibition of L. monocytogenes.

scholarly journals STUDI BACILLUS FIRMUS SEBAGAI KANDIDAT PROBIOTIK DALAM MENGHADAPI Aeromonas hydrophila PADA MEDIA BUDIDAYA The Study of Bacillus firmus as Probiotic Candidate in Supressing Aeromonas hydrophila in Culture Media

2016 ◽  
Vol 11 (2) ◽  
pp. 111
Author(s):  
Alfabetian Harjuno Condro Haditomo ◽  
Angela Mariana Lusiastuti ◽  
Widanarni Widanarni
Keyword(s):  
Aeromonas Hydrophila ◽  
Pathogenic Bacteria ◽  
Culture Media ◽  
Inhibition Zone ◽  
Probiotic Bacteria ◽  
Bacterial Disease ◽  
Second Phase ◽  
Bacillus Firmus ◽  
Culture Methods

ABSTRAK   Pengendalian penyakit bakterial yang umum dilakukan dengan pemakaian antibiotik atau  bahan kimia sudah tidak diperbolehkan lagi karena menimbulkan patogen yang resisten  terhadap bahan kimia tersebut, terlebih jika penggunaan tidak sesuai dengan anjuran yang diberikan. Dampak negatif terhadap kesehatan konsumen berupa residu antibiotik juga menjadi pertimbangan yang harus diperhatikan. Manipulasi terhadap populasi mikroba yang berada di perairan guna pencegahan sebelum terjadinya serangan bakteri yang bersifat mematikan perlu dilakukan sebagaimana konsep probiotik sebagai biokontrol. Tujuan penelitian ini adalah menguji kandidat probiotik dalam menekan atau menghambat bakteri patogen Aeromonas hydrophila. Penelitian ini dilaksananakan dalam dua tahap. Tahap pertama adalah tahap pengujian bakteri kandidat probiotik secara in vitro menggunakan metode zona hambat dan kultur bersama pada media agar.  Tahap kedua adalah uji tentang bakteri kandidat probiotik dengan patogen pada media budidaya. Hasil terbaik penelitian tahap pertama pada  uji kultur bersama antara kandidat probiotik B. firmus dengan A. hydrophila pada skala in vitro adalah dengan penambahan probiotik  B. firmus sebanyak 108 cfu/ml. Sedangkan pada penelitian tahap kedua didapatkan hasil berturut-turut perlakuan D dengan tingkat kelangsungan hidup (SR) mencapai 90%, perlakuan C dengan SR 75%, perlakuan A dengan SR 50% dan perlakuan K dengan SR 50%.   Kata kunci: Bacillus firmus, probiotik, Aeromonas hydrophila, media budidaya   ABSTRACT  Controlling bacterial disease with the use of antibiotics or chemicals is no longer allowed as it results in pathogens that are resistant to the chemicals, especially when not in accordance with the recommendations provided. The negative impactsof the antibiotics residues on the consumers’ health  also need to be considered. Manipulation of microbial populations present in the waters as preventation before the lethal attack of bacteria needs to be done which is in accordance with the concept of probiotics as biocontrol.The purpose of this study was to test the probiotic candidates in suppressing or inhibiting pathogenic bacteria Aeromonas hydrophila. This study was conducted in two stages. The first stage was to test a candidate probiotic bacteria in vitro using culture methods and inhibition zone on the media together. The second stage wasto test candidate probiotic bacteria to pathogens on the cultivation media. The best results in the first phase of the research is shared culture test between probiotic candidate B. FIRMUS with A. hydrophila on vitro scale is the addition of the probiotic B. FIRMUS 108 cfu / ml. While in the second phase of the research results obtained successively: treatment D with a survival rate (SR) reaches 90%, treatment C with SR 75%, treatment A with SR 50% and treatment K with SR 50%. Keywords: Bacillus FIRMUS, probiotics, Aeromonas hydrophila, media cultivation

Biological parameters, immune enzymes, and histological alterations in the livers of grass carp infected with Aeromonas hydrophila

2017 ◽  
Vol 70 ◽  
pp. 121-128 ◽  
Author(s):  
Shen-Tong Wang ◽  
Xin-Zhan Meng ◽  
Li-Sen Li ◽  
Yun-Fei Dang ◽  
Yuan Fang ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Grass Carp ◽  
Biological Parameters ◽  
Histological Alterations
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