scholarly journals Isolation and Characterization of Ochrobactrum tritici for Penicillin V Potassium Degradation

mSphere ◽  
2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Peng Wang ◽  
Chen Shen ◽  
Kaili Xu ◽  
Qinqin Cong ◽  
Zhe Dong ◽  
...  

ABSTRACT Substantial concentrations of penicillin V potassium (PVK) have been found in livestock manure, soil, and wastewater effluents, which may pose potential threats to human health and contribute to the emergence of penicillin-resistant bacterial strains. In this study, bacterial strains capable of degrading PVK were isolated from sludge and characterized. Strain X-2 was selected for biodegradation of PVK. Based on morphological observations and 16S rRNA gene sequencing, strain X-2 was identified as an Ochrobactrum tritici strain. To enhance the PVK degradation ability of PVK, a whole-cell biodegradation process of Ochrobactrum tritici X-2 was established and optimized. In the whole-cell biodegradation process, the optimal temperature and pH were 30°C and 7.0, respectively. Under the optimized conditions, the degradation rate using 0.5 mg/ml PVK reached 100% within 3 h. During biodegradation, two major metabolites were detected: penicilloic acid and phenolic acid. The present study provides a novel method for the biodegradation of PVK using Ochrobactrum tritici strains, which represent promising candidates for the industrial biodegradation of PVK. IMPORTANCE Substantial concentrations of penicillin V potassium (PVK) have been found in the environment, which may pose potential threats to human health and contribute to the emergence of penicillin-resistant bacterial strains. In this study, antibiotic-degrading bacterial strains for PVK were isolated from sludge and characterized. Ochrobactrum tritici was selected for the biodegradation of PVK with high efficiency. To enhance its PVK degradation ability, a whole-cell biodegradation process was established and optimized using Ochrobactrum tritici. The degradation rate with 0.5 mg/ml PVK reached 100% within 3 h. The potential biodegradation pathway was also investigated. To the best of our knowledge, the present study provides new insights into the biodegradation of PVK using an Ochrobactrum tritici strain, a promising candidate strain for the industrial biodegradation of β-lactam antibiotics.

2014 ◽  
Vol 80 (14) ◽  
pp. 4199-4206 ◽  
Author(s):  
Camilo Muñoz ◽  
Catalina Hidalgo ◽  
Manuel Zapata ◽  
David Jeison ◽  
Carlos Riquelme ◽  
...  

ABSTRACTIn this study, we designed and evaluated a microalgal pretreatment method using cellulolytic bacteria that naturally degrades microalgae in their native habitat. Bacterial strains were isolated from each of two mollusk species in a medium containing 1% carboxymethyl cellulose agar. We selected nine bacterial strains that had endoglucanase activity: five strains fromMytilus chilensis, a Chilean mussel, and four strains fromMesodesma donacium, a clam found in the Southern Pacific. These strains were identified phylogenetically as belonging to the generaAeromonas,Pseudomonas,Chryseobacterium, andRaoultella. The cellulase-producing capacities of these strains were characterized, and the degradation of cell walls inBotryococcus brauniiandNannochloropsis gaditanawas tested with “whole-cell” cellulolytic experiments.Aeromonas bivalviumMA2,Raoultella ornithinolyticaMA5, andAeromonas salmonicidaMC25 degradedB. braunii, andR. ornithinolyticaMC3 and MA5 degradedN. gaditana. In addition,N. gaditanawas pretreated withR. ornithinolyticastrains MC3 and MA5 and was then subjected to an anaerobic digestion process, which increased the yield of methane by 140.32% and 158.68%, respectively, over that from nonpretreated microalgae. Therefore, a “whole-cell” cellulolytic pretreatment can increase the performance and efficiency of biogas production.


2011 ◽  
Vol 77 (18) ◽  
pp. 6531-6538 ◽  
Author(s):  
Keren Buhnik-Rosenblau ◽  
Yael Danin-Poleg ◽  
Yechezkel Kashi

ABSTRACTThe gut microbiota is strongly associated with the well-being of the host. Its composition is affected by environmental factors, such as food and maternal inoculation, while the relative impact of the host's genetics have been recently uncovered. Here, we studied the effect of the host genetic background on the composition of intestinal bacteria in a murine model, focusing on lactic acid bacteria (LAB) as an important group that includes many probiotic strains. Based on 16S rRNA gene genotyping, variation was observed in fecal LAB populations of BALB/c and C57BL/6J mouse lines.Lactobacillus johnsonii, a potentially probiotic bacterium, appeared at significantly higher levels in C57BL/6J versus BALB/c mouse feces. In the BALB/c gut, theL. johnsoniilevel decreased rapidly after oral administration, suggesting that some selective force does not allow its persistence at higher levels. The genetic inheritance ofL. johnsoniilevels was further tested in reciprocal crosses between the two mouse lines. The resultant F1 offspring presented similarL. johnsoniilevels, confirming that mouse genetics plays a major role in determining these levels compared to the smaller maternal effect. Our findings suggest that mouse genetics has a major effect on the composition of the LAB population in general and on the persistence ofL. johnsoniiin the gut in particular. Concentrating on a narrow spectrum of culturable LAB enables the isolation and characterization of such potentially probiotic bacterial strains, which might be specifically oriented to the genetic background of the host as part of a personalized-medicine approach.


2016 ◽  
Vol 4 (3) ◽  
pp. 288-293
Author(s):  
Rashmi Parihar ◽  
Sumit Kumar Dubey

Phenol and its derivatives are consistently causing harmful effects to an aquatic ecosystem. The present study focused on the isolation and characterization of potential phenol degrading bacterial strains and subsequently optimization of media ingredients for efficient phenol degradation by potential bacterial strains. Bacterial strains were isolated from municipal sewage, Bilaspur (21'47 and 23'8 N 81'14 and 83'15 E). After optimization phenol degradation rate was increased by 1.84 fold for PDB 5 (from 40.37% to 74.67%) and 1.39 fold for PDB 11 (from 58.62% to 81.51%) at 500mg/l initial phenol concentration. PDB 5 and PDB 11 were identified as Streptococcus sp. PDB 5 and Pseudomonas sp. PDB 11 respectively as potential phenol degrading bacterial strains. These strains can further be used in microbially assisted phenol degradation to remove phenol derivatives present in industrial wastewater.Int J Appl Sci Biotechnol, Vol 4(3): 288-293  


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Peng Wang ◽  
Chen Shen ◽  
Qinqin Cong ◽  
Kaili Xu ◽  
Jialin Lu

Abstract Background Biodegradation of antibiotics is a promising method for the large-scale removal of antibiotic residues in the environment. However, the enzyme that is involved in the biodegradation process is the key information to be revealed. Results In this study, the beta-lactamase from Ochrobactrumtritici that mediates the biodegradation of penicillin V was identified and characterized. When searching the proteins of Ochrobactrumtritici, the β-lactamase (OtLac) was identified. OtLac consists of 347 amino acids, and predicted isoelectric point is 7.0. It is a class C β-lactamase according to BLAST analysis. The coding gene of OtLac was amplified from the genomic DNA of Ochrobactrumtritici. The OtLac was overexpressed in E. coli BL21 (DE3) and purified with Ni2+ column affinity chromatography. The biodegradation ability of penicillin V by OtLac was identified in an in vitro study and analyzed by HPLC. The optimal temperature for OtLac is 32 ℃ and the optimal pH is 7.0. Steady-state kinetics showed that OtLac was highly active against penicillin V with a Km value of 17.86 μM and a kcat value of 25.28 s−1 respectively. Conclusions OtLac demonstrated biodegradation activity towards penicillin V potassium, indicating that OtLac is expected to degrade penicillin V in the future.


2020 ◽  
Vol 86 (11) ◽  
Author(s):  
Christopher C. Cheng ◽  
Rebbeca M. Duar ◽  
Xiaoxi Lin ◽  
Maria Elisa Perez-Munoz ◽  
Stephanie Tollenaar ◽  
...  

ABSTRACT Cross-feeding based on the metabolite 1,2-propanediol has been proposed to have an important role in the establishment of trophic interactions among gut symbionts, but its ecological importance has not been empirically established. Here, we show that in vitro growth of Lactobacillus reuteri (syn. Limosilactobacillus reuteri) ATCC PTA 6475 is enhanced through 1,2-propanediol produced by Bifidobacterium breve UCC2003 and Escherichia coli MG1655 from the metabolization of fucose and rhamnose, respectively. Work with isogenic mutants showed that the trophic interaction is dependent on the pduCDE operon in L. reuteri, which encodes the ability to use 1,2-propanediol, and the l-fucose permease (fucP) gene in B. breve, which is required for 1,2-propanediol formation from fucose. Experiments in gnotobiotic mice revealed that, although the pduCDE operon bestows a fitness burden on L. reuteri ATCC PTA 6475 in the mouse digestive tract, the ecological performance of the strain was enhanced in the presence of B. breve UCC2003 and the mucus-degrading species Bifidobacterium bifidum. The use of the respective pduCDE and fucP mutants of L. reuteri and B. breve in the mouse experiments indicated that the trophic interaction was specifically based on 1,2-propanediol. Overall, our work established the ecological importance of cross-feeding relationships based on 1,2-propanediol for the fitness of a bacterial symbiont in the vertebrate gut. IMPORTANCE Through experiments in gnotobiotic mice that employed isogenic mutants of bacterial strains that produce (Bifidobacterium breve) and utilize (Lactobacillus reuteri) 1,2-propanediol, this study provides mechanistic insight into the ecological ramifications of a trophic interaction between gut symbionts. The findings improve our understanding on how cross-feeding influences the competitive fitness of L. reuteri in the vertebrate gut and revealed a putative selective force that shaped the evolution of the species. The findings are relevant since they provide a basis to design rational microbial-based strategies to modulate gut ecosystems, which could employ mixtures of bacterial strains that establish trophic interactions or a personalized approach based on the ability of a resident microbiota to provide resources for the incoming microbe.


2011 ◽  
Vol 77 (15) ◽  
pp. 5394-5401 ◽  
Author(s):  
Emilie Lyautey ◽  
Amandine Cournet ◽  
Soizic Morin ◽  
Stéphanie Boulêtreau ◽  
Luc Etcheverry ◽  
...  

ABSTRACTElectroactivity is a property of microorganisms assembled in biofilms that has been highlighted in a variety of environments. This characteristic was assessed for phototrophic river biofilms at the community scale and at the bacterial population scale. At the community scale, electroactivity was evaluated on stainless steel and copper alloy coupons used both as biofilm colonization supports and as working electrodes. At the population scale, the ability of environmental bacterial strains to catalyze oxygen reduction was assessed by cyclic voltammetry. Our data demonstrate that phototrophic river biofilm development on the electrodes, measured by dry mass and chlorophyllacontent, resulted in significant increases of the recorded potentials, with potentials of up to +120 mV/saturated calomel electrode (SCE) on stainless steel electrodes and +60 mV/SCE on copper electrodes. Thirty-two bacterial strains isolated from natural phototrophic river biofilms were tested by cyclic voltammetry. Twenty-five were able to catalyze oxygen reduction, with shifts of potential ranging from 0.06 to 0.23 V, cathodic peak potentials ranging from −0.36 to −0.76 V/SCE, and peak amplitudes ranging from −9.5 to −19.4 μA. These isolates were diversified phylogenetically (Actinobacteria,Firmicutes,Bacteroidetes, andAlpha-,Beta-, andGammaproteobacteria) and exhibited various phenotypic properties (Gram stain, oxidase, and catalase characteristics). These data suggest that phototrophic river biofilm communities and/or most of their constitutive bacterial populations present the ability to promote electronic exchange with a metallic electrode, supporting the following possibilities: (i) development of electrochemistry-based sensors allowingin situphototrophic river biofilm detection and (ii) production of microbial fuel cell inocula under oligotrophic conditions.


2014 ◽  
Vol 82 (5) ◽  
pp. 1744-1754 ◽  
Author(s):  
Tram N. Cao ◽  
Zhuyun Liu ◽  
Tran H. Cao ◽  
Kathryn J. Pflughoeft ◽  
Jeanette Treviño ◽  
...  

ABSTRACTDespite the public health challenges associated with the emergence of new pathogenic bacterial strains and/or serotypes, there is a dearth of information regarding the molecular mechanisms that drive this variation. Here, we began to address the mechanisms behind serotype-specific variation between serotype M1 and M3 strains of the human pathogenStreptococcus pyogenes(the group AStreptococcus[GAS]). Spatially diverse contemporary clinical serotype M3 isolates were discovered to contain identical inactivating mutations within genes encoding two regulatory systems that control the expression of important virulence factors, including the thrombolytic agent streptokinase, the protease inhibitor-binding protein-G-related α2-macroglobulin-binding (GRAB) protein, and the antiphagocytic hyaluronic acid capsule. Subsequent analysis of a larger collection of isolates determined that M3 GAS, since at least the 1920s, has harbored a 4-bp deletion in thefasCgene of thefasBCAXregulatory system and an inactivating polymorphism in therivRregulator-encoding gene. ThefasCandrivRmutations in M3 isolates directly affect the virulence factor profile of M3 GAS, as evident by a reduction in streptokinase expression and an enhancement of GRAB expression. Complementation of thefasCmutation in M3 GAS significantly enhanced levels of the small regulatory RNA FasX, which in turn enhanced streptokinase expression. Complementation of therivRmutation in M3 GAS restored the regulation ofgrabmRNA abundance but did not alter capsule mRNA levels. While important, thefasCandrivRmutations do not provide a full explanation for why serotype M3 strains are associated with unusually severe invasive infections; thus, further investigation is warranted.


2015 ◽  
Vol 26 (3) ◽  
pp. 389-406 ◽  
Author(s):  
Maria Francesca Milazzo ◽  
Francesco Spina

Purpose – The purpose of this paper is to quantify the human health impacts of soy-biodiesel production with the aim to discuss about its environmental sustainability. Design/methodology/approach – The integrated use of two current approaches, risk assessment (RA) and life cycle assessment (LCA), has allowed improvement of the potentialities of both in obtaining a more complete analysis. The implementation of a life cycle indicator for the assessment of the impacts on the human health, integrating the features of both approaches, is the main focus of this paper. Findings – It has been found that, although the biodiesel is a green fuel, it has some criticalities in its life cycle, which cannot be disregarded. In fact, even if biodiesel is essentially a clean fuel there are some phases, prior to the industrial phase, that can cause negative effects on human health and ecosystems. Practical implications – Results suggest some measures which can be adopted to substantially reduce human health impacts. Further alternative could be analysed in future to gain more insight about the use of biodiesel fuels. Originality/value – The estimation of the impacts of a process producing biodiesel has been made by using a novel approach. The novelty is associated with the calculation of the impacts on human health by using the transfer factors applied in RA. The use of such factors, properly modified in order to estimate the impacts on a wider scale than a site-dimension, allows defining a holistic approach, as LCA and RA are used as complete units but at the same time can be related to each other.


2002 ◽  
Vol 68 (9) ◽  
pp. 4390-4398 ◽  
Author(s):  
S. A. F. T. van Hijum ◽  
G. H. van Geel-Schutten ◽  
H. Rahaoui ◽  
M. J. E. C. van der Maarel ◽  
L. Dijkhuizen

ABSTRACT Fructosyltransferase (FTF) enzymes produce fructose polymers (fructans) from sucrose. Here, we report the isolation and characterization of an FTF-encoding gene from Lactobacillus reuteri strain 121. A C-terminally truncated version of the ftf gene was successfully expressed in Escherichia coli. When incubated with sucrose, the purified recombinant FTF enzyme produced large amounts of fructo-oligosaccharides (FOS) with β-(2→1)-linked fructosyl units, plus a high-molecular-weight fructan polymer (>107) with β-(2→1) linkages (an inulin). FOS, but not inulin, was found in supernatants of L. reuteri strain 121 cultures grown on medium containing sucrose. Bacterial inulin production has been reported for only Streptococcus mutans strains. FOS production has been reported for a few bacterial strains. This paper reports the first-time isolation and molecular characterization of (i) a Lactobacillus ftf gene, (ii) an inulosucrase associated with a generally regarded as safe bacterium, (iii) an FTF enzyme synthesizing both a high molecular weight inulin and FOS, and (iv) an FTF protein containing a cell wall-anchoring LPXTG motif. The biological relevance and potential health benefits of an inulosucrase associated with an L. reuteri strain remain to be established.


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