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Satya Eswari Jujjavarapu, Swasti Dhagat
The increase in antibiotic-resistant strains of pathogens has created havoc worldwide. These antibiotic-resistant pathogens require potent drugs for their inhibition. Lipopeptides, which are produced as secondary metabolites by many microorganisms, have the ability to act as potent safe drugs. Lipopeptides are amphiphilic molecules containing a lipid chain bound to the peptide. They exhibit broad-spectrum activities against both bacteria and fungi. Other than their antimicrobial properties, they have displayed anti-cancer properties as well, but their mechanism of action is not understood...
December 7, 2017: Probiotics and Antimicrobial Proteins
Bárbara C S Farias, Denise C Hissa, Camila T M do Nascimento, Samuel A Oliveira, Davila Zampieri, Marcos N Eberlin, Deivid L S Migueleti, Luiz F Martins, Maíra P Sousa, Danuza N Moyses, Vânia M M Melo
Cyclic lipopeptides (CLPs) are non-ribosomal biosurfactants produced by Bacillus species that exhibit outstanding interfacial activity. The synthesis of CLPs is under genetic and environmental influence, and representatives from different families are generally co-produced, generating isoforms that differ in chemical structure and biological activities. This study to evaluate the effect of low and high NaCl concentrations on the composition and surface activity of CLPs produced by Bacillus strains TIM27, TIM49, TIM68, and ICA13 towards microbial enhanced oil recovery (MEOR)...
December 7, 2017: Applied Microbiology and Biotechnology
Pengfei Jin, Haonan Wang, Wenbo Liu, Weiguo Miao
BACKGROUND: Bacillus spp. have prominent ability to suppress plant pathogens and corresponding diseases. Previous analyses of Bacillus spp. revealed numerous gene clusters involved in nonribosomal synthesis of cyclic lipopeptides with distinct antimicrobial action. The 4'-phosphopantetheinyl transferase (PPTase) encoded by sfp gene is a key factor in lipopeptide synthesis in Bacillus spp. In previous study, B. amyloliquefaciens strain HAB-2 was found to inhibit a broad range of plant pathogens, which was attributed to its secondary metabolite lipopeptide...
December 4, 2017: BMC Microbiology
Qi Deng, Yuehua Pu, Lijun Sun, Yaling Wang, Yang Liu, Rundong Wang, Jianmeng Liao, Defeng Xu, Ying Liu, Riying Ye, Zhijia Fang, Ravi Gooneratne
Shewanella putrefaciens biofilm formation is of great concern for the shrimp industry because it adheres easily to food and food-contact surfaces and is a source of persistent and unseen contamination that causes shrimp spoilage and economic losses to the shrimp industry. Different concentrations of an antimicrobial lipopeptide, the fermentation product of Bacillus subtilis, AMPNT-6, were tested for the ability to reduce adhesion and disrupt S. putrefaciens preformed biofilms on two different contact surfaces (shrimp shell, stainless steel sheet)...
December 2017: Food Research International
Jie Wang, Xu-Hua Nong, Muhammad Amin, Shu-Hua Qi
Several ansamycins have been reported to inhibit bacterial biofilm formation and accelerate the eradication of developed biofilms, but little is known about the effect of hygrocin C, an ansamycin, on bacterial biofilm formation. Here, hygrocin C was isolated from the marine-derived Streptomyces sp. SCSGAA 0027 and reported for the first time to be capable of inhibiting the biofilm formation of Staphylococcus aureus and Bacillus amyloliquefaciens SCSGAB0082 with the production of anti-microbial lipopeptides from South China Sea gorgonian Subergorgia suberosa at concentrations of less than minimum inhibitory concentrations...
November 30, 2017: Applied Microbiology and Biotechnology
Satya Eswari Jujjavarapu, Swasti Dhagat, Vinay Kurrey
Due to increase in antibiotic-resistance among pathogens, there is a need for potent and safe drugs. An alternative to antibiotics is lipopeptides which are produced as a secondary metabolite by many microorganisms. They exhibit broad-spectrum activities against pathogens along with anti-cancer properties. Among various lipopeptides produced by microorganisms, daptomycin, surfactin, and polymyxin have gained popularity as medicines but their mechanism of action is not described properly. In silico drug design of these lipopeptides becomes a challenge due to their complex structures...
November 29, 2017: Current Drug Targets
Mohamed Seghir Daas, Jeella Z Acedo, Albert Remus R Rosana, Fabini D Orata, Béla Reiz, Jing Zheng, Farida Nateche, Rebecca J Case, Salima Kebbouche-Gana, John C Vederas
In this study, we identified a new Bacillus strain isolated from an Algerian salty lake that produces metabolites that are active against Gram-positive and Gram-negative bacteria, as well as fungal pathogens. The draft genome sequence of the strain is presented herein. Genome sequence analysis identified the strain to be B. amyloliquefaciens subspecies plantarum F11, and showed that the strain carries the gene clusters for the production of a number of bioactive and surface-active compounds. These include the lipopeptides surfactin and fengycin, antibacterial polyketides macrolactin and bacillaene, and a putative novel lanthipeptide, among others...
November 23, 2017: FEMS Microbiology Letters
Kirk A Reynolds, Hanna Luhavaya, Jie Li, Samira Dahesh, Victor Nizet, Kazuya Yamanaka, Bradley S Moore
In the ongoing effort to unlock the chemical potential of marine bacteria, genetic engineering of biosynthetic gene clusters (BGCs) is increasingly used to awake or improve expression of biosynthetic genes that may lead to discovery of novel bioactive natural products. Previously, we reported the successful capture, engineering and heterologous expression of an orphan BGC from the marine actinomycete Saccharomonospora sp. CNQ-490, which resulted in the isolation of the novel lipopeptide antibiotic taromycin A...
November 29, 2017: Journal of Antibiotics
Saima Khalid, Joshua A Baccile, Joseph E Spraker, Joanna Tannous, Muhammad Imran, Frank C Schroeder, Nancy P Keller
Bacterial-fungal interactions are presumed to be mediated chiefly by small-molecule signals; however, little is known about the signaling networks that regulate antagonistic relationships between pathogens. Here we show that the ralstonins, lipopeptides produced by the plant pathogenic bacteria Ralstonia solanacearum, interfere with germination of the plant-pathogenic fungus Aspergillus flavus by down-regulating expression of a cryptic biosynthetic gene cluster (BGC), named imq. Comparative metabolomic analysis of overexpression strains of the transcription factor ImqK revealed imq-dependent production of a family of tripeptide-derived alkaloids, the imizoquins...
November 28, 2017: ACS Chemical Biology
Renyu Ding, Ganqiong Xu, Yan Feng, Lin Zou, Wei Chao
N-Formyl-Met-Leu-Phe (fMLP), a mimic of N-formyl oligopeptides that are released from bacteria, is a potent leukocyte chemotactic factor. It induces intracellular calcium ([Ca]i) transient that is important for various neutrophil biological functions, e.g., adhesion, ROS and cytokine productions. Toll-like receptors (TLRs), an essential part of host innate immunity, regulate neutrophil activities, but their role in [Ca]i signaling is less clear. In the current study, we examined the effect of several TLR ligands, including Pam3Cys4 (TLR1/2), lipopolysaccharide (LPS, TLR4), and lipoteichoic acid (LTA, TLR2/6), on calcium signaling and on the fMLP-induced [Ca]i transients in mouse neutrophils loaded with Fura-2/AM...
November 15, 2017: Shock
Mandana Ohadi, Hamid Forootanfar, Hamid Reza Rahimi, Elham Jafari, Mojtaba Shakibaie, Touba Eslaminejad, Gholamreza Dehghannoudeh
BACKGROUND: Recently, the development of a safe bioactive material with antioxidant properties, in which can improve healing activity are focusing. Biosurfactants are very famous for their antimicrobial and free radical scavenging activities. Thereof, the main aim of the present study was to investigate the antioxidant and wound healing activity of the lipopeptide biosurfactant (LBS) produced by Acinetobacter junii B6. DPPH radical scavenging activities and FRAP assays were used to measure the antioxidant properties...
November 22, 2017: Current Pharmaceutical Biotechnology
Prasad Aiyar, Daniel Schaeme, María García-Altares, David Carrasco Flores, Hannes Dathe, Christian Hertweck, Severin Sasso, Maria Mittag
Photosynthetic unicellular organisms, known as microalgae, are key contributors to carbon fixation on Earth. Their biotic interactions with other microbes shape aquatic microbial communities and influence the global photosynthetic capacity. So far, limited information is available on molecular factors that govern these interactions. We show that the bacterium Pseudomonas protegens strongly inhibits the growth and alters the morphology of the biflagellated green alga Chlamydomonas reinhardtii. This antagonistic effect is decreased in a bacterial mutant lacking orfamides, demonstrating that these secreted cyclic lipopeptides play an important role in the algal-bacterial interaction...
November 24, 2017: Nature Communications
Yexuan Mao, Lanlan Yu, Mengfan Mao, Chuanguo Ma, Lingbo Qu
Type 2 diabetes mellitus, a kind of conformational disease, has become an epidemic disease, which seriously endangers the quality of life and health of human beings. The deposition of human islet amyloid polypeptide (hIAPP) has been considered as one of the major pathological features of type 2 diabetes mellitus. As lipopeptides have some hydrophobic groups, which are similar to the reported aggregation inhibitors, and some lipopeptides could prevent cells from depositing of amyloid fibrils, several potential lipopeptide inhibitors have been engineered and synthesized, which have been assessed for their inhibitory effect in preventing amyloid fibrils formation of hIAPP11-20 by using the conventional thioflavin-T fluorescence assay and new technique microscale thermophoresis (MST)...
November 21, 2017: Journal of Peptide Science: An Official Publication of the European Peptide Society
Jessica L Chitty, Mark S Butler, Azzah Suboh, David J Edwards, Matthew A Cooper, James A Fraser, Avril A B Robertson
Resistance to antimicrobials is a growing problem in both developed and developing countries. In nations where AIDS is most prevalent, the human fungal pathogen Cryptococcus neoformans is a significant contributor to mortality, and its growing resistance to current antifungals an ever-expanding threat. We investigated octapeptin C4, from the cationic cyclic lipopeptide class of antimicrobials, as a potential new antifungal. Octapeptin C4 was a potent, selective inhibitor of this fungal pathogen with minimum inhibitory concentration of 1...
November 20, 2017: Antimicrobial Agents and Chemotherapy
Lingling Kong, Kadi Liis Saar, Raphael Jacquat, Liu Hong, Aviad Levin, Hongze Gang, Ruqiang Ye, Bozhong Mu, Tuomas P J Knowles
Many biological molecules are by their nature amphiphilic and have the ability to act as surfactants, stabilizing interfaces between aqueous and immiscible oil phases. In this paper, we explore the adsorption kinetics of surfactin, a naturally occurring cyclic lipopeptide, at hexadecane/water interfaces and compare and contrast its adsorption behaviour with that of synthetic alkyl benzene sulfonate isomers, through direct measurements of changes in interfacial tension upon surfactant adsorption. We access millisecond time resolution in kinetic measurements by making use of droplet microfluidics to probe the interfacial tension of hexadecane droplets dispersed in a continuous water phase through monitoring their deformation when the droplets are exposed to shear flows in a microfluidic channel with regular corrugations...
December 6, 2017: Interface Focus
Fang Cao, Min Xiong, Shunyi Li, Huawan Cai, Yufang Sun, Sheng Yang, Xin Liu, Rong Zhu, Xuejing Yu, Xingguo Wang
Pseudomonas syringae pv. syringae van Hall CFCC 1336 (Pss 1336) is the causal agent of bacterial disease of stone fruit trees, and also able to elicit hypersensitive response (HR) in non-host tobacco. It is known that this pathogen uses PCS-pathway to synthesize phosphatidylcholine (PC), and mutation of the pcs gene abolishes bacterial PC synthesis. Previous study also found that the 1336 pcs(-) mutant lacking PC in its membrane phospholipids was unable to secrete HrpZ harpin and elicit HR in non-host plants...
January 2018: Microbiological Research
Bo Yun, Kade D Roberts, Philip E Thompson, Roger L Nation, Tony Velkov, Jian Li
Polymyxins (polymyxin B and colistin) are cyclic lipopeptide antibiotics that serve as a last-line defence against Gram-negative "superbugs". In the present study, two novel fluorescent polymyxin probes were designed through regio-selective modifications of the polymyxin B core structure at the N-terminus and the hydrophobic motif at positions 6 and 7. The resulting probes, FADDI-285 and FADDI-286 demonstrated comparable antibacterial activity (MICs 2-8 mg/L) to polymyxin B and colistin (MICs 0.5-8 mg/L) against a panel of gram-negative clinical isolates of Acinetobacter baumannii, Klebsiella pneumoniae and Pseudomonas aeruginosa...
November 11, 2017: Sensors
Sun Hee Moon, Xuan Zhang, Guangrong Zheng, Daniel G Meeker, Mark S Smeltzer, En Huang
We report the structure-activity relationship analyses of 17 linear lipopeptide paenipeptin analogues. Analogues 7, 12, and 17 were more potent than the lead compound. Analogue 17 was active against carbapenem-resistant and polymyxin-resistant pathogens. This compound at 40 μg/mL resulted in 3 log and 2.6 log reductions of methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, respectively, in catheter-associated biofilms in vitro. Analogue 17 showed little hemolysis at 32 μg/mL and lysed 11% of red blood cells at 64 μg/mL...
November 22, 2017: Journal of Medicinal Chemistry
Thibaut Thery, Yvonne O'Callaghan, Nora O'Brien, Elke K Arendt
The design of novel efficient antimicrobial peptides (AMPs) faces several issues, such as cost of synthesis, proteolytic stability or cytotoxicity. The identification of key determinants involved in the activity of AMPs, such as cationicity and amphipathicity, allowed the synthesis of short peptides with optimized properties. An ultrashort peptide made of the sequence H-Orn-Orn-Trp-Trp-NH2 (O3TR) showed antifungal activity against several contaminants from food products. This peptide inhibited the growth of the filamentous fungi Fusarium culmorum, Penicillium expansum and Aspergillus niger within a range of concentration of 12...
November 8, 2017: International Journal of Food Microbiology
Yuan-Seng Wu, Siew-Ching Ngai, Bey-Hing Goh, Kok-Gan Chan, Learn-Han Lee, Lay-Hong Chuah
Surfactin, a cyclic lipopeptide biosurfactant produced by various strains of Bacillus genus, has been shown to induce cytotoxicity against many cancer types, such as Ehrlich ascites, breast and colon cancers, leukemia and hepatoma. Surfactin treatment can inhibit cancer progression by growth inhibition, cell cycle arrest, apoptosis, and metastasis arrest. Owing to the potent effect of surfactin on cancer cells, numerous studies have recently investigated the mechanisms that underlie its anticancer activity...
2017: Frontiers in Pharmacology
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