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Background: A novel lytic bacteriophage (phage) was isolated with Pseudomonas mendocina strain STP12 (P. mendocina) from the untreated site of Sewage Treatment Plant of Lovely Professional University, India. P. mendocina is a Gram-negative, rod-shaped, aerobic bacterium belonging to the family Pseudomonadaceae and has been reported in fifteen (15) cases of economically important diseases worldwide. Methods and results: Here, a novel phage specifically infecting and killing P. mendocina strain STP12 was isolated from sewage sample using enrichment, spot test and double agar overlay (DAOL) method and was designated as vB_PmeS_STP12. The phage vB-PmeS-STP12 was viable at wide range of pH and temperature ranging from 4 to10 and − 20 to 70 °C respectively. Host range and efficiency of plating (EOP) analysis indicated that phage vB-PmeS-STP12 was capable of infecting and killing P. mendocina strain STP6 with EOP of 0.34. Phage vB_PmeS_STP12 was found to have a significant bacterial reduction (p < 0.005) at all the doses administered, particularly at optimal MOI of 1 PFU/CFU, compared to the control. Morphological analysis using high resolution transmission electron microscopy (HR-TEM) revealed an icosahedral capsid of ~ 55 nm in diameter on average with a short, non-contractile tail. The genome of vB_PmeS_STP12 is a linear, dsDNA containing 36,212 bp in size with a GC content of 58.87% harbouring 46 open reading frames (ORFs). The 46 predicted ORFs encode proteins with functional information categorized as lysis, replication, packaging, regulation, assembly, infection, immune, and hypothetical. However, the genome of vB_PmeS_STP12 appeared to be devoid of tRNAs, integrase gene, toxins genes, virulence factors, antimicrobial resistance genes (ARGs) and CRISPR arrays. The blast analysis with phylogeny revealed that vB_PmeS_STP12 is genetically similar to Pseudomonas phage PMBT14, Pseudomonas phage Almagne and Serratia phage Serbin with a highest identity of 74.00%, 74.93% and 59.48% respectively. Conclusions: Taken together, characterization, morphological analysis and genome-informatics indicated that vB_PmeS_STP12 is podovirus morphotype belonging to the class Caudoviticetes, family Zobellviridae which appeared to be devoid of integrase gene, ARGs, CRISPR arrays, virulence factors and toxins genes, exhibiting stability and infectivity at wide range of pH (4 to10) and temperature (–20 to 70 °C), thereby making vB_PmeS_STP12 suitable for phage therapy or biocontrol. Based on the bibliometric analysis and data availability with respect to sequences deposited in GenBank, this is the first report of a phage infecting Pseudomonas mendocina. [ABSTRACT FROM AUTHOR]

Background: A novel lytic bacteriophage (phage) was isolated with Pseudomonas mendocina strain STP12 (P. mendocina) from the untreated site of Sewage Treatment Plant of Lovely Professional University, India. P. mendocina is a Gram-negative, rod-shaped, aerobic bacterium belonging to the family Pseudomonadaceae and has been reported in fifteen (15) cases of economically important diseases worldwide. Methods and results: Here, a novel phage specifically infecting and killing P. mendocina strain STP12 was isolated from sewage sample using enrichment, spot test and double agar overlay (DAOL) method and was designated as vB_PmeS_STP12. The phage vB-PmeS-STP12 was viable at wide range of pH and temperature ranging from 4 to10 and − 20 to 70 °C respectively. Host range and efficiency of plating (EOP) analysis indicated that phage vB-PmeS-STP12 was capable of infecting and killing P. mendocina strain STP6 with EOP of 0.34. Phage vB_PmeS_STP12 was found to have a significant bacterial reduction (p < 0.005) at all the doses administered, particularly at optimal MOI of 1 PFU/CFU, compared to the control. Morphological analysis using high resolution transmission electron microscopy (HR-TEM) revealed an icosahedral capsid of ~ 55 nm in diameter on average with a short, non-contractile tail. The genome of vB_PmeS_STP12 is a linear, dsDNA containing 36,212 bp in size with a GC content of 58.87% harbouring 46 open reading frames (ORFs). The 46 predicted ORFs encode proteins with functional information categorized as lysis, replication, packaging, regulation, assembly, infection, immune, and hypothetical. However, the genome of vB_PmeS_STP12 appeared to be devoid of tRNAs, integrase gene, toxins genes, virulence factors, antimicrobial resistance genes (ARGs) and CRISPR arrays. The blast analysis with phylogeny revealed that vB_PmeS_STP12 is genetically similar to Pseudomonas phage PMBT14, Pseudomonas phage Almagne and Serratia phage Serbin with a highest identity of 74.00%, 74.93% and 59.48% respectively. Conclusions: Taken together, characterization, morphological analysis and genome-informatics indicated that vB_PmeS_STP12 is podovirus morphotype belonging to the class Caudoviticetes, family Zobellviridae which appeared to be devoid of integrase gene, ARGs, CRISPR arrays, virulence factors and toxins genes, exhibiting stability and infectivity at wide range of pH (4 to10) and temperature (–20 to 70 °C), thereby making vB_PmeS_STP12 suitable for phage therapy or biocontrol. Based on the bibliometric analysis and data availability with respect to sequences deposited in GenBank, this is the first report of a phage infecting Pseudomonas mendocina. [ABSTRACT FROM AUTHOR]

Siderophores are low-molecular-weight and high-affinity molecules produced by bacteria under iron-limited conditions. Due to the low iron (III) (Fe+3) levels in surface waters in the marine environment, microbes produce a variety of siderophores. In the current study, halophilic bacteria Bacillus taeanensis SMI_1, Enterobacter sp., AABM_9, and Pseudomonas mendocina AMPPS_5 were isolated from marine surface water of Kalinga beach, Bay of Bengal (Visakhapatnam, Andhra Pradesh, India) and were investigated for siderophore production using the Chrome Azurol S (CAS) assay. The effect of various production parameters was also studied. The optimum production of siderophores for SMI_1 was 93.57% siderophore units (SU) (after 48 h of incubation at 30 °C, pH 8, sucrose as carbon source, sodium nitrate as nitrogen source, 0.4% succinic acid), and for AABM_9, it was 87.18 %SU (after 36 h of incubation period at 30 °C, pH 8, in the presence of sucrose, ammonium sulfate, 0.4% succinic acid). The maximum production of siderophores for AMPPS_5 was 91.17 %SU (after 36 h of incubation at 35 °C, pH 8.5, glucose, ammonium sulfate, 0.4% citric acid). The bacterial isolates SMI_1, AABM_9, and AMPPS_5 showed siderophore production at low Fe+3 concentrations of 0.10 µM, 0.01 µM, and 0.01 µM, respectively. The SMI_1 (73.09 %SU) and AMPPS_5 (68.26 %SU) isolates showed siderophore production in the presence of Zn+2 (10 µM), whereas AABM_9 (50.4 %SU) exhibited siderophore production in the presence of Cu+2 (10 µM). Additionally, these bacterial isolates showed better heavy-metal chelation ability and rapid development in seed germination experiments. Based on these results, the isolates of marine-derived bacteria effectively produced the maximum amount of siderophores, which could be employed in a variety of industrial and environmental applications. [ABSTRACT FROM AUTHOR]

An extracellular esterase (HP) with polybutylene succinate (PBS)-degrading ability was identified from Pseudomonas mendocina SA-1503. The HP also had the ability to degrade poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and polycaprolactone. This HP had optimal activity at pH 9.0 and 40 °C and remained stable at pH 8.0–9.0 and temperatures of 30–40 °C. Mn2+ promoted the enzyme activity. HP could hydrolyze all p -NP fatty acid ester substrates containing even numbers of carbon atoms from C2 to C18 and had the highest catalytic activity for the p -NP C6 substrate. After 60 h of HP-catalyzed degradation, PBS films experienced a weight loss of more than 60%. Butanedioic acid, 1,4-butanediol, and a series of oligomers were detected in the degradation products of PBS by HP. Further structural analysis of HP revealed that it could be classified as a microbial esterase of α / β hydrolase superfamily and contained a conserved catalytic triad structure (Ser-148, Asp-198, and His-228) with a relatively exposed active site. [Display omitted] • An extracellular esterase(HP) was obtained from Bacillus safensis. • HP has the ability to degrade PBS, PCL and P34HB, with the best degradation ability for PBS. • HP belongs to α/β hydrolase superfamily with a conserved catalytic triad structure. [ABSTRACT FROM AUTHOR]

Siderophores are low-molecular-weight and high-affinity molecules produced by bacteria under iron-limited conditions. Due to the low iron (III) (Fe+3) levels in surface waters in the marine environment, microbes produce a variety of siderophores. In the current study, halophilic bacteria Bacillus taeanensis SMI_1, Enterobacter sp., AABM_9, and Pseudomonas mendocina AMPPS_5 were isolated from marine surface water of Kalinga beach, Bay of Bengal (Visakhapatnam, Andhra Pradesh, India) and were investigated for siderophore production using the Chrome Azurol S (CAS) assay. The effect of various production parameters was also studied. The optimum production of siderophores for SMI_1 was 93.57% siderophore units (SU) (after 48 h of incubation at 30 °C, pH 8, sucrose as carbon source, sodium nitrate as nitrogen source, 0.4% succinic acid), and for AABM_9, it was 87.18 %SU (after 36 h of incubation period at 30 °C, pH 8, in the presence of sucrose, ammonium sulfate, 0.4% succinic acid). The maximum production of siderophores for AMPPS_5 was 91.17 %SU (after 36 h of incubation at 35 °C, pH 8.5, glucose, ammonium sulfate, 0.4% citric acid). The bacterial isolates SMI_1, AABM_9, and AMPPS_5 showed siderophore production at low Fe+3 concentrations of 0.10 µM, 0.01 µM, and 0.01 µM, respectively. The SMI_1 (73.09 %SU) and AMPPS_5 (68.26 %SU) isolates showed siderophore production in the presence of Zn+2 (10 µM), whereas AABM_9 (50.4 %SU) exhibited siderophore production in the presence of Cu+2 (10 µM). Additionally, these bacterial isolates showed better heavy-metal chelation ability and rapid development in seed germination experiments. Based on these results, the isolates of marine-derived bacteria effectively produced the maximum amount of siderophores, which could be employed in a variety of industrial and environmental applications.

Pseudomonas mendocina, a Gram-negative, aerobic bacillus, has rarely been implicated in human infections. This report details the first documented case of catheter-associated urinary tract infection (CAUTI) caused by P. mendocina in a COVID-19-positive patient. We present the case of a 70-year-old male with obstructive uropathy who presented with altered mental status eight days after testing positive for COVID-19. Urine cultures identified P. mendocina and Enterococcus faecalis. The antibiotic regimen was adjusted to cefepime and fosfomycin for coverage against P. mendocina and E. faecalis, respectively, resulting in the patient's improvement and discharge with an outpatient course of ciprofloxacin. However, the patient was readmitted 12 days later for recurrent symptoms and traumatic catheter removal, requiring nephrostomy tube placement. Follow-up revealed severe bladder and prostate abnormalities, confirming a complex interplay of factors contributing to his infection. P. mendocina is a rare opportunistic pathogen, often occurring in patients with pre-existing health conditions. This case is significant as the first CAUTI caused by P. mendocina and highlights potential links between COVID-19 and increased susceptibility to bacterial infections. The patient's comorbidities, particularly obstructive uropathy, and prolonged catheter use, were likely major factors in his infection. The role of COVID-19 in facilitating bacterial colonization remains speculative but warrants further investigation. This case report underscores the need for heightened clinical awareness and prompt intervention in patients with similar risk factors. The successful treatment regimen provides a valuable reference for managing such infections. Further research is needed to explore the interplay between viral and bacterial infections, particularly in the context of COVID-19., Competing Interests: Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Penney et al.)

The problem of nitrate accumulation in aerobic tank and total nitrogen excessive discharge in effluent was very common in traditional livestock and poultry farming wastewater treatment systems owing to the lengthy process flow and low process control level. A strain LYX of aerobic bacterium was isolated from the activated sludge of a wastewater treatment system in a pig farm, which could remove nitrate effectively in aerobic tank and was identified Pseudomonas mendocina by 16S rRNA sequencing. Under the condition of nitrate as the sole nitrogen source, this strain removed over 90% of NO3−-N with an initial concentration of 110 mg/L under aerobic conditions within 48 hours. Among them, 37.9% of NO3− -N was assimilated into Bio-N, about 51.9% was reduced to gaseous nitrogen and less than 0.5% of nitrogen was replaced by NO3−-N and NH4+-N, 9.7% NO3−-N remained in the effluent at the end. At the same time, four key genes (napA, nirK, norB and nosZ) related to nitrate nitrogen removal were expressed during the denitrification process of P. mendocina LYX, in which the transcription level of the indicator genes of this aerobic denitrifying bacterium (napA) was the highest. In addition, it was found with the 15N tracer technique that inoculation of this strain on sludge increased the amount of nitrogen loss from 9.26 nmol N/(g·h) to 23.835 nmol N/(g·h). Therefore, P. medocina LYX is a potential bioagent for advanced nitrogen removal by assimilating and reducing nitrate simultaneously in aerobic tanks. [ABSTRACT FROM AUTHOR]

Heterotrophic nitrifying and aerobic denitrifying bacteria that have been widely isolated from complicated activated sludge microflorae demonstrate dominant advantages in simultaneous removal of ammonium and nitrogen oxides under aerobic conditions. However, owing to the need of organic carbon to support bacterial growth, nitrogen removal of actual industrial wastewater with low carbon-to-nitrogen (C/N) ratio remains a challenge. Here, Pseudomonas mendocina Y7 was identified and presented to effectively remove nitrogen of actual refinery wastewater with low C/N ratio. The isolated bacterium showed high removal efficiency of NH 4 + –N, NO 2 − –N, and NO 3 − –N up to about 90% in single (100 mg/L) or mixed (200 mg/L) nitrogen source media at low C/N ratio of 6 when it was cultivated for 12 or 21 h. According to PCR amplification, the heterotrophic nitrification and aerobic denitrification capability of strain Y7 was attributed to the functional genes of amoA , hao , napA , and nirS. In activated sludge process for treating actual refinery wastewater with low C/N ratio, compared to abundant accumulation of NO 2 − –N and NO 3 − –N only using the activated sludge, strain Y7 significantly improved the removal efficiency of NH 4 + ‒N and total nitrogen (with influent concentrations of about 40 and 55 mg/L) from about 47% and 22% to about 85% and 73%, respectively, without the accumulation of nitrogen oxides. Microbial community structure analysis revealed that strain Y7 could coexist well with other microorganisms in the activated sludge and maintain highly efficient and steady nitrogen removal in continuous treatment system. This discovery provides a promising treatment approach toward actual nitrogen-rich industrial wastewater. [Display omitted] • A novel heterotrophic nitrifying and aerobic denitrifying bacterium is identified. • The isolated strain Y7 shows high nitrogen removal efficiency at low C/N ratio. • Strain Y7 maintains highly efficient and steady nitrogen removal in a continuous system. • This work provides a promising treatment approach toward actual industrial wastewater. [ABSTRACT FROM AUTHOR]

The rising production and consumption of plastics, coupled with their intrinsic robustness, has resulted in the accumulation of up to 200 million tons of plastic waste in landfills and the environment each year. Of all these synthetic polymers, polyethylene terephthalate (PET) is the most widely used in the world. As environmental microorganisms have begun evolving their own biological means to metabolize plastics, they potentially present a sustainable method to recycle PET and retain its material value for subsequent use through biodegradation. Here, we evaluate the feasibility of using multiple PET-degrading bacterial strains (Thermobifida fusca, Ideonella sakaiensis, Pseudomonas mendocina) concurrently to develop an industrial co-culture solution. The growth behavior of each strain was evaluated at temperatures ranging from 30-60 °C and in a Hipolypepton-based media. UV-treated PET pellets were then incubated in monoculture and co-culture cell suspensions for 2 days, and degradation was measured through a spectrophotometric assay. A 1:1 T. fusca/I. sakaiensis co-culture was found to achieve a higher biodegradation efficiency compared to I. sakaiensis monoculture but not compared to T. fusca monoculture, suggesting the need for further optimization of degradation conditions. Although our studies demonstrate the great potential of biodegradation as a solution for the plastic waste crisis, the direct application of microbes may not be suitable for industrial use when compared to alternative biodegradative methods. [ABSTRACT FROM AUTHOR]

The widely prescribed pharmaceutical metformin and its main metabolite, guanylurea, are currently two of the most common contaminants in surface and wastewater. Guanylurea often accumulates and is poorly, if at all, biodegraded in wastewater treatment plants. This study describes Pseudomonas mendocina strain GU, isolated from a municipal wastewater treatment plant, using guanylurea as its sole nitrogen source. The genome was sequenced with 36-fold coverage and mined to identify guanylurea degradation genes. The gene encoding the enzyme initiating guanylurea metabolism was expressed, and the enzyme was purified and characterized. Guanylurea hydrolase, a newly described enzyme, was shown to transform guanylurea to one equivalent (each) of ammonia and guanidine. Guanidine also supports growth as a sole nitrogen source. Cell yields from growth on limiting concentrations of guanylurea revealed that metabolism releases all four nitrogen atoms. Genes encoding complete metabolic transformation were identified bioinformatically, defining the pathway as follows: guanylurea to guanidine to carboxyguanidine to allophanate to ammonia and carbon dioxide. The first enzyme, guanylurea hydrolase, is a member of the isochorismatase-like hydrolase protein family, which includes biuret hydrolase and triuret hydrolase. Although homologs, the three enzymes show distinct substrate specificities. Pairwise sequence comparisons and the use of sequence similarity networks allowed fine structure discrimination between the three homologous enzymes and provided insights into the evolutionary origins of guanylurea hydrolase. [ABSTRACT FROM AUTHOR]

Background: Pseudomonas mendocina is a gram-negative bacterium belonging to the Pseudomonas genus. It rarely causes infection in humans. To date, there have only been fourteen previous cases of Pseudomonas mendocina infection published worldwide.Case report: Here, we present the case of a 64-year-old man, with a complex past medical history, who presented to a UK hospital with signs of sepsis, including high-grade fever. Admission bloods showed raised inflammatory markers consistent with infection. On day two of admission, blood cultures tested positive for Pseudomonas mendocina, as confirmed by MALDI-TOF. Results: The patient received intravenous piperacillin/tazobactam, based on antimicrobial sensitivities, and made a good clinical recovery. He was discharged home after two weeks in hospital. Conclusion: In conclusion, we present the first reported UK case of Pseudomonas mendocina bacteraemia, adding further data regarding the epidemiology, pathogenesis and clinical treatment of this unusual infection.

Pseudomonas mendocina NK-01 previously isolated by our lab is able to accumulate medium-chain-length polyhydroxyalkanoate (mcl-PHA) intracellularly and secrete alginate oligosaccharide (AO) to the extracellular milieu. The present study aimed at investigating whether improved production of mcl-PHA and AO by P. mendocina can be accomplished by genome reduction. In this study, 14 large genomic fragments accounting for 7.7% of the genome of P. mendocina NK-01 were sequentially deleted to generate a series of genome-reduced strains by an upp -based markerless knockout method. As a result, the intracellular ATP/ADP ratio of the strain NKU421 with the largest deletion improved by 11 times compared to NK-01. More importantly, the mcl-PHA and AO yields of NKU421 increased by 114.8% and 27.8%, respectively. Enhancing mcl-PHA and AO production by NKU421 may be attributed to improved transcriptional levels of PHA synthase genes and AO secretion-related genes. The present study suggests that rational reduction of bacterial genome is a feasible approach to construct an optimal chassis for enhanced production of bacterial metabolites. In the future, further reduction of the NKU421 genome can be expected to create high-performance chassis for the development of microbial cell factories. Unlabelled Image • The genome of P. mendocina NK-01 is reduced by 7.7% to construct a chassis NKU421. • Genome reduction greatly improves energy metabolism in NKU421. • Genome reduction enhances mcl-PHA and AO production by NKU421. • Further reduction of the NKU421 genome can create minimal genome cell factory. [ABSTRACT FROM AUTHOR]

Squalene hopene cyclases catalyse the conversion of a linear substrate squalene to a cyclic product with high stereo-selectivity.The enzyme squalene hopene cyclase from Pseudomonas mendocina expressed in E. coli BL21 (DE3) was evaluated for its synthetic drug transforming ability. Nine synthetic drugs were selected as substrates for biotransformation reactions by the enzyme. The homology modelling of the protein and docking of the selected ligands were performed using GOLD suite docking software. The drug which showed maximum binding with the active-site residues of the enzyme was selected for biotransformation studies. On transformation with the enzyme, Glibenclamide, the selected antidiabetic drug alone showed significant changes in the FT/IR spectra; hence, it was selected for LCMS analysis to confirm the transformations. From the chromatogram and MS spectra, the mono-oxygenation of the product due to the enzymatic activity was confirmed. The drug transforming ability of the purified SHC could be used as an ideal tool for the generation of new and active substrate derivatives. [ABSTRACT FROM AUTHOR]

In this study, six genes involved in β -oxidation pathway of P. mendocina NK-01 were deleted to construct mutant strains NKU-∆ β1 and NKU-∆ β5. Compared with the wild strain NKU, the mcl-PHA titers of NKU-∆ β5 were respectively increased by 5.58- and 4.85-fold for culturing with sodium octanoate and sodium decanoate. And the mcl-PHA titers of NKU-∆ β1 was increased by 10.02-fold for culturing with dodecanoic acid. The contents of dominant monomers 3-hydroxydecanoate (3HD) and 3-hydroxydodecanoate (3HDD) of the mcl-PHA synthesized by NKU-∆ β5 were obviously increased to 90.01 and 58.60 mol%, respectively. Further deletion of genes phaG and phaZ , the 3HD and 3HDD contents were further improved to 94.71 and 68.67 mol%, respectively. The highest molecular weight of mcl-PHA obtained in this study was 80.79 × 104 Da, which was higher than the previously reported mcl-PHA. With the increase of dominant monomer contents, the synthesized mcl-PHA showed better thermal properties, mechanical properties and crystallization properties. Interestingly, the cell size of NKU-∆ β5 was larger than that of NKU due to the accumulation of more PHA granules. This study indicated that a systematically metabolic engineering approach for P. mendocina NK-01 could significantly improve the mcl-PHA titer, dominant monomer contents and physical properties of mcl-PHA. Unlabelled Image • The mcl-PHA titer was improved by inhibition of the β -oxidation pathway. • Knockout of phaZ improved the contents of the dominant monomer of mcl-PHA. • The physical properties of mcl-PHA were improved. • The cell morphology obviously changed for the β -oxidation pathway inhibition strains. [ABSTRACT FROM AUTHOR]

Abstract Root exudates are chemical compounds that are released from living plant roots and provide significant energy, carbon, nitrogen and phosphorus sources for microbes inhabiting the rhizosphere. The exudates shape the microflora associated with the plant, as well as influences the plant health and productivity. Therefore, a better understanding of the trophic link that is established between the plant and the associated bacteria is necessary. In this study, a comprehensive survey on the utilization of grapevine and rootstock related organic acids were conducted on a vineyard soil isolate which is Pseudomonas mendocina strain S5.2. Phenotype microarray analysis has demonstrated that this strain can utilize several organic acids including lactic acid, succinic acid, malic acid, citric acid and fumaric acid as sole growth substrates. Complete genome analysis using single molecule real-time technology revealed that the genome consists of a 5,120,146 bp circular chromosome and a 252,328 bp megaplasmid. A series of genetic determinants associated with the carbon utilization signature of the strain were subsequently identified in the chromosome. Of note, the coexistence of genes encoding several iron–sulfur cluster independent isoenzymes in the genome indicated the importance of these enzymes in the events of iron deficiency. Synteny and comparative analysis have also unraveled the unique features of d-lactate dehydrogenase of strain S5.2 in the study. Collective information of this work has provided insights on the metabolic role of this strain in vineyard soil rhizosphere.

Objective: Rare disease Background: Pseudomonas mendocina is a Gram-negative, aerobic, rod-shaped bacterium belonging to the family Pseudomonadaceae. In nature, P. mendocina has been isolated from water and soil samples. The species rarely causes disease in humans though severe infections resulting in hospitalization and intensive care have been documented. This case is perhaps the second reported case in the United States of a P. mendocina related infection. In this case report, we analyze the clinical and laboratory features of P. mendocina infection in a severely immunocompromised acquired immunodeficiency syndrome (AIDS) patient and review the available literature. Case Report: A 64-year-old white male with past medical history significant for human immunodeficiency virus (HIV)/AIDS (CD4 count on admission <10 cells/mm3) diagnosed in 1988 and on antiretroviral therapy since 1992, was admitted to our facility for acute management of a suspected invasive mold infection. On hospital day 20 the patient developed a fever of 39.9°C, had an elevated lactate of 2.6 mmol/L and absolute neutrophil count greater than 1000 cells/mm3. On hospital day 22, both blood culture sets were positive for Pseudomonas mendocina. Antibiotic therapy was de-escalated to ceftazidime and after a total treatment course of 10 days the was successfully discharged. Conclusions: There have been 14 reported cases of P. mendocina in the world. Four cases presented with meningitis and 5 with endocarditis. Beyond typical anti-pseudomonal agents, 2 of the reported cases show susceptibility of P. mendocina antibiotics such as sulfamethoxazole/trimethoprim and ceftriaxone. All documented case reports of P. mendocina infection resulted in successful treatment with antibiotics and survival of the patient. [ABSTRACT FROM AUTHOR]

Polyhydroxyalkanoates (PHAs) can be produced by microorganisms from renewable resources and are regarded as promising bioplastics to replace petroleum-based plastics. A medium-chain-length PHAs (mcl-PHA)-producing strain Pseudomonas mendocina NK-01 was isolated previously by our lab and its whole-genome sequence is currently available. Morphology engineering of manipulating cell morphology-related genes has been applied for enhanced accumulation of the intracellular biopolymer short-chain-length PHAs (scl-PHA). However, it has not yet been reported to improve the yield of mcl-PHA by morphology engineering so far. In this work, several well-characterized cell morphology-related genes, including the cell fission ring (Z-ring) location genes minCD, peptidoglycan degradation gene nlpD, actin-like cytoskeleton protein gene mreB, Z-ring formation gene ftsZ, and FtsZ inhibitor gene sulA, were intensively investigated for their impacts on the cell morphology and mcl-PHA accumulation by gene knockout and overexpression in P. mendocina NKU, a upp knockout mutant of P. mendocina NK-01. For a minCD knockout mutant P. mendocina NKU-∆minCD, the average cell length was obviously increased and the mcl-PHA production was improved. However, the nlpD knockout mutant had a shorter cell length and lower mcl-PHA yield compared with P. mendocina NKU. Overexpression of mreB in P. mendocina NKU resulted in spherical cells. When ftsZ was overexpressed in P. mendocina NKU, the cell division was accelerated and the mcl-PHA titer was improved. Furthermore, mreB, ftsZ, or sulA was overexpressed in P. mendocina NKU-∆minCD. Consequently, the mcl-PHA titers were all increased compared with P. mendocina NKU-∆minCD carrying the empty vector. The multiple fission pattern was finally achieved in ftsZ-overexpressing NKU-∆minCD. In this work, improved production of mcl-PHA in P. mendocina NK-01 has been achieved by morphology engineering. This work provides an alternative strategy to enhance mcl-PHA accumulation in mcl-PHA-producing strains. [ABSTRACT FROM AUTHOR]

Pseudomonas mendocina is a Gram-negative, rod-shaped, aerobic bacterium that belongs in the family Pseudomonadaceae and has been isolated from water and soil. Even though it is thought to cause infections quite rarely in humans, it can cause severe infections even in immunocompetent individuals. The aim of this study was to systemically review all cases of human infection by P. mendocina in the literature and describe their epidemiology, microbiology, antimicrobial susceptibility, treatment and outcomes. Thus, a systematic review of PubMed for studies providing epidemiological, clinical, microbiological as well as treatment data and outcomes of Pseudomonas mendocina infections was conducted. In total, 12 studies, containing data of 16 patients, were included. The commonest P. mendocina infections were infective endocarditis, central nervous system infections and skin and soft tissue infections (SSTIs). Fever was the main presenting symptom, while sepsis was evident in almost half the patients. Pseudomonas mendocina was susceptible to most antibiotics tested. Mortality was low in all different infection types. Third or fourth generation cephalosporins and quinolones are the commonest agents used for treatment, irrespectively of the infection site.

The purpose of this research was to analyze the functional portraits and genomic features of carbapenem-resistant Pseudomonas mendocina carrying NDM-1 and IMP-1 . The resistance mechanism of the strain was verified by in vivo experiments. Genomic data were aligned and analyzed in the NCBI database. Growth curve measurements were used to describe the growth characteristics of the bacteria. The virulence of P. mendocina strain was analyzed by serum killing assay and biofilm formation assay. Plasmid conjugation experiments were performed to verify the transferability of plasmids carrying drug-resistance genes. The P. mendocina strain was highly resistant to carbapenems. In addition, ST typing is unknown and has been submitted to Genebank. The strain carried two carbapenemase genes, including NDM-1 and IMP-1 . Among them, blaNDM-1 was located on a 5.62832 Mb chromosome, and blaIMP-1 was located on a 172.851 Kb transferable plasmid, which was a very close relative of pIMP-NY7610 in China. The strain also had a variety of virulence genes, which were expressed in the siderophore, capsule, pilus, alginate, flagella, etc. The study suggests that the functional portrait and genomic features of carbapenem-resistant P. mendocina harboring blaNDM-1 and blaIMP-1 are unique to China. This outcome represents antibiotic resistance exhibited in the genus Pseudomonas by acquiring chromosomes and plasmid genes. The monitoring and supervision of antimicrobial usage must be strengthened since the multi-drug-resistant and moderately virulent P. mendocina will attract much attention in the near future.

Objectives: An extracellular protease inhibitor (BTPI-301) of trypsin was purified and characterized from an isolate of Pseudomonas mendocina. Results: BTPI-301was purified to homogeneity by (NH)SO, precipitation, DEAE Sepharose and CNBr-activated Sepharose chromatography. Homogeneity was proved by native PAGE and SDS-PAGE. The intact molecular mass was 11567 Da by MALDI-TOF analysis. BTPI-301was a competitive inhibitor with a Ki of 3.5 × 10 M. It was stable and active at pH 4-12 and also at 4-90 °C for 1 h. Peptide mass fingerprinting by MALDI revealed that the BTPI-301 is a new inhibitor not reported so far with protease inhibitory activity. The pI of the inhibitor was 3.8. The stoichiometry of trypsin-BTPI-301 interaction is 1:1. The inhibitor was specific towards trypsin. Conclusion: A pH tolerant and thermostable protease inhibitor BTPI-301 active against trypsin was purified and characterized from P. mendocina that could be developed and used as biopreservative as well as biocontrol agent. [ABSTRACT FROM AUTHOR]

Nitrogen (N) and phosphorous (P) removal by a single bacterium could improve the biological reaction efficiency and reduce the operating cost and complexity in wastewater treatment plants (WWTPs). Here, an isolated strain was identified as Pseudomonas mendocina SCZ-2 and showed high performance of heterotrophic nitrification (HN) and aerobic denitrification (AD) without intermediate accumulation. During the AD process, the nitrate removal efficiency and rate reached a maximum of 100% and 47.70 mg/L/h, respectively, under optimal conditions of sodium citrate as carbon source, a carbon-to-nitrogen ratio of 10, a temperature of 35 °C, and shaking a speed of 200 rpm. Most importantly, the strain SCZ-2 could rapidly and simultaneously eliminate N and P with maximum NH 4 +-N, NO 3 −-N, NO 2 −-N, and PO 4 3−-P removal rates of 14.38, 17.77, 20.13 mg N/L/h, and 2.93 mg P/L/h, respectively. Both the N and P degradation curves matched well with the modified Gompertz model. Moreover, the amplification results of functional genes, whole genome sequencing, and enzyme activity tests provided theoretical support for simultaneous N and P removal pathways. This study deepens our understanding of the role of HN-AD bacteria and provides more options for simultaneous N and P removal from actual sewage. [Display omitted] • A novel strain SCZ-2 was isolated and identified as Pseudomonas mendocina. • Strain SCZ-2 showed highly efficient and effective HN-AD capability. • Rapid simultaneous N and P removal was achieved with a high efficiency. • Proposed metabolic pathway of N and P removal was demonstrated. [ABSTRACT FROM AUTHOR]

[Display omitted] • An aerobic denitrifying microbe, HITSZ-D1, was identified as Pseudomonas mendocina. • Strain D1 has extremely high denitrification efficiency and enzyme activities. • The environmental threshold of strain D1 is extensive. • Strain D1 efficiently metabolizes various nitrogen types without accumulating nitrite. A highly efficient aerobic denitrifying microbe was isolated from sewage sludge by using a denitrifier enrichment strategy based on decreasing carbon content. The microbe was identified as Pseudomonas mendocina HITSZ-D1 (hereafter, D1). Investigation of the conditions under which D1 grew and denitrified revealed that it performed good growth and nitrate removal performance under a wide range of conditions. In particular, D1 rapidly removed all types of inorganic nitrogen without accumulation of the intermediate products nitrite and nitrous oxide. Overall, D1 showed a total nitrogen removal efficiency >96% at a C/N ratio of 8. The biotransformation modes and fates of three typical types of inorganic nitrogen were also assessed. Moreover, D1 had significantly higher denitrification efficiency and enzyme activities than other aerobic denitrifying microbes (Paracoccus denitrificans , Pseudomonas aeruginosa , and Pseudomonas putida). These results suggest that D1 has great potential for treating wastewater containing high concentrations of nitrogen. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate- co-4-hydroxybutyrate) (P(3HB- co-4HB)) is a biodegradable plastic that is extensively utilized in many fields. In this work, P(3HB- co-4HB) powder was degraded by Pseudomonas mendocina for the preparation of low-molecular-mass (LMW) P(3HB- co-4HB). After degradation, the remaining P(3HB- co-4HB) powder was analyzed via gel permeation chromatography (GPC), differential scanning calorimetry (DSC), X-ray powder diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and proton nuclear magnetic resonance (H NMR) spectroscopy. The degradation of P(3HB- co-4HB) by P. mendocina occurred in two stages: the fast degradation stage (0-8 h) and the slow degradation stage (8-24 h). GPC analysis showed that the molecular weight of P(3HB- co-4HB) gradually decreased with degradation time. After 24 h of degradation, the weight-average molecular weight of P(3HB- co-4HB) was reduced to 4-5 kDa. DSC and XRD analyses both verified that the degree of crystallinity decreased with prolonged degradation time. The melting temperature of the degraded powder, however, remained unchanged. FTIR and H NMR analyses of the degraded powder showed that no new material was produced during degradation. Thus, the degradation of P(3HB- co-4HB) by P. mendocina could be used to produce LMW P(3HB- co-4HB) for use in various applications, such as the synthesis of amphiphilic block copolymers. [ABSTRACT FROM AUTHOR]

Removal of poly aromatic hydrocarbons (PAHs) from waste water is a challenging task due to their hydrophobic and persistent nature. The present study investigated the efficiency of Pseudomonas mendocina for PAH biodegradation. Biodegradation of PAHs acenapthene and naphthalene was studied and the process was optimized with the Central Composite Design (CCD) feature of Response Surface Methodology (RSM). Toxicity analysis of the untreated and bio treated solutions were conducted on a comparative scale using Cicer arietinum (chickpea) in terms of oxidative stress, germination studies and biochemical parameters. Almost 98.8% and 98.6% degradation of acenaphthene and naphthalene respectively by Pseudomonas mendocina was recorded under RSM optimized conditions. Results of the toxicity analysis further indicated that the bio-treated solutions were fit to be reused or discharged, thereby establishing the potential of Pseudomonas mendocina for biodegradation applications in wide scale. [ABSTRACT FROM AUTHOR]

Endosulfan contamination is one of the major concerns of soil ecosystem, which causes detrimental effects not only to humans but also to animals and plants. Therefore, the aim of this study was to isolate and identify a novel bacterial strain capable of degrading endosulfan in agriculture contaminated soils. A novel bacterial strain was isolated from the sugarcane field contaminated with endosulfan, and was named as ZAM1 strain. The ZAM1 bacterial strain was further identified as Pseudomonas mendocina based on the biochemical and molecular analysis. 16sRNA sequence analysis of ZAM1 strain shows maximum similarity with known endosulfan-degrading bacteria ( Pseudomonas putida), respectively. Enrichment was carried out using the endosulfan as sole sulfur source. The ZAM1 strain was able to use α and β endosulfan as a sole sulfur source. Our results showed that ZAM1 strain degrades endosulfan >64.5% (50 mg/l) after 12 days of incubation. The residues were analyzed by GC-MS analysis and confirmed the formation of metabolites of dieldrin, 2 heptanone, methyl propionate, and endosulfan lactone compounds. Hence, these results indicate that the ZAM1 strain is a promising bacterial source for detoxification of endosulfan residues in the environment. [ABSTRACT FROM AUTHOR]

Root exudates are chemical compounds that are released from living plant roots and provide significant energy, carbon, nitrogen and phosphorus sources for microbes inhabiting the rhizosphere. The exudates shape the microflora associated with the plant, as well as influences the plant health and productivity. Therefore, a better understanding of the trophic link that is established between the plant and the associated bacteria is necessary. In this study, a comprehensive survey on the utilization of grapevine and rootstock related organic acids were conducted on a vineyard soil isolate which is Pseudomonas mendocina strain S5.2. Phenotype microarray analysis has demonstrated that this strain can utilize several organic acids including lactic acid, succinic acid, malic acid, citric acid and fumaric acid as sole growth substrates. Complete genome analysis using single molecule real-time technology revealed that the genome consists of a 5,120,146 bp circular chromosome and a 252,328 bp megaplasmid. A series of genetic determinants associated with the carbon utilization signature of the strain were subsequently identified in the chromosome. Of note, the coexistence of genes encoding several iron-sulfur cluster independent isoenzymes in the genome indicated the importance of these enzymes in the events of iron deficiency. Synteny and comparative analysis have also unraveled the unique features of d-lactate dehydrogenase of strain S5.2 in the study. Collective information of this work has provided insights on the metabolic role of this strain in vineyard soil rhizosphere. [ABSTRACT FROM AUTHOR]

Poly(3-hydroxybutyrate-co-hydroxyvalerate) (PHBV) is a biodegradable polymer synthesized in microorganisms. The application of PHBV is limited by certain material disadvantages. Poly(ε-caprolactone) (PCL) possesses excellent thermodynamic and mechanical properties and was used to modify PHBV in the presence of triethyl citrate (TEC) and dicumyl peroxide (DCP), which was used as plasticizer and grafting agent, respectively. The effects of PCL and additive agents on the mechanical, thermal, amphipathic and degradability behaviors of the blends were investigated. The results showed that the mechanical properties of the PHBV blends improved by PCL incorporation and improved even further after TEC and DCP addition. The addition of DCP could not induce an increase in crystallization temperature but improved the crystallization degree of the blends. The presence of hydrophilic groups in TEC leads to an apparent increases in the hydrophilicity of the PHBV blends. A PHBV/PCL blend (40/60) with TEC (20 wt.%) and DCP (0.5 wt.%) was chosen for its good mechanical properties and hydrophilicity. The chosen ratio of the blends was also shown a preferable degradation activity by biodegradation assay using Pseudomonas mendocina. The addition of TEC and DCP has no conspicuous negative effect on the biodegradation. [ABSTRACT FROM AUTHOR]

In natural settings, microbes often associate closely with surfaces and interfaces called biofilms and adhere in an extracellular matrix. The biofilm provide diverse microenvironments and high resistance to environmental stress on the constituent cells that aid to generate cellular heterogeneity and phenotypic variability. The work presented here examines for the first time the capability of Pseudomonas mendocina EGD-AQ5 biofilm-associated cells, compared with that of planktonic cells to utilize toxic intermediate catechol under benzoate degradation conditions in liquid culture systems. Both planktonic and biofilm-associated cells utilized benzoate to the same extent but accumulated catechol differently. This differential catechol accumulation activity of the Pseudomonas mendocina EGD-AQ5 could be accredited to the cells adapted as a biofilm. Further experiments with transcriptome implicated to increased expression of genes like pelA (involved in biofilm formation) cat1,2D (ortho pathway) and decreased expression of cat2,3D (meta pathway) in biofilm harvested cells than free suspended cells. Whole genome sequence analysis of Pseudomonas mendocina EGD-AQ5 (Genbank Accession No AVQF00000000 ) deciphered catechol ortho and meta-pathways for benzoate utilization and pelABCDEFG as involved in biofilm formation. These results suggest that Pseudomonas mendocina EGD-AQ5 biofilms should facilitate bioaugmentation to be more resilient and efficient bioremediation technology than free suspended planktonic cells. [ABSTRACT FROM AUTHOR]

Magnetic whole-cell biocatalysts (MWCBs) for enzymatic biodiesel production from soybean oil were constructed by immobilizing Pseudomonas mendocina cells into Fe 3 O 4 -chitosan microspheres. The effects of the MWCBs concentration, temperature, the molar ratio of methanol to oil and water content on biodiesel yield were studied. For the MWCBs, a biodiesel yield of 87.32% was obtained under the optimum operating condition (MWCBs concentration of 10 wt.%, water content of 10 wt.%, 35 °C, methanol to oil molar ratio of 4:1 and a four-step addition of methanol) for 48 h. The kinetic data followed Michaelis-Menten model ( r max , 2.1801 mg/min;  K m , 0.4272 mg/mL;  K I , 0.2308 mg/mL) with competitive inhibition by methanol. MWCBs had an excellent reusability and still gave a biodiesel yield of 83.57% after 10 cycles, which was higher than that of Fe 3 O 4 -uncontained whole cell biocatalysts (74.06%). Moreover, MWCBs could be separated and be recycled easily due to their superparamagnetism. Therefore, MWCBs would be promising for large-scale biodiesel industry. [ABSTRACT FROM AUTHOR]

Conditions for the optimal production of polyhydroxyalkanoate (PHA) byPseudomonas mendocinaPSU using a biodiesel liquid waste (BLW) were determined by response surface methodology. These were an initial carbon to nitrogen ratio (C/N) of 40 (mole/mole), an initial pH of 7.0, and a temperature of 35 °C. A biomass and PHA concentration of 3.65 g/L and about 2.6 g/L (77% DCW), respectively, were achieved in a growth associated process using 20 g/L glycerol in the BLW after 36 h of exponential growth. The PHA monomer compositions were 3HB (3-hydroxybutyrate), a short-chain-length-PHA, and the medium-chain-length-PHA e.g. 3-hydroxyoctanoate and 3-hydroxydecanoate. Both thephbCandphaCgenes were characterized. ThephbCenzyme had not been previously detected in aPseudomonas mendocinaspecies. A 2.15 g/L of an exopolysaccharide, alginate, was also produced with a similar composition to that of otherPseudomonasspecies. PHA biosynthesis from biodiesel liquid waste (BLW) byPseudomonas mendocinaPSU. [ABSTRACT FROM AUTHOR]

In the present investigation an attempt has been made to demineralize the Gondwana coal of Gopinathpur top and bottom seams of Mugma mine, Raniganj coalfield, Dhanbad with the help of Pseudomonas mendocina strain B6-1. The change in the amount of ash yield and decrease in the concentration of selected minor elements like Na, K, Mn and Ca and environmentally sensitive selected trace elements such as Cd, Pb, Se, Ni, Mn, and Zn have been studied as a function of time of bacterial treatment as well as with variation in the bacterial biomass. After 28 days of bacterial treatment there was variable amount of decrease observed in ash yield as well as in the concentration of minor and trace elements. The removal of the elements was further enhanced with the increase in the bacterial biomass from 10 to 25 mg/mL. Due to over exploitation of superior grade coals in the country, the remaining coal resources, available for current use, are inferior in grade and contain high level of impurities and there is ample scope of bio-beneficiation of these coals using bacterial biomass. [ABSTRACT FROM AUTHOR]

Objectives: To enhance the biosynthesis of medium-chain-length polyhydroxyalkanoates (PHA) from glucose in Pseudomonas mendocina NK-01, metabolic engineering strategies were used to block or enhance related pathways. Results: Pseudomonas mendocina NK-01 produces PHA from glucose. Besides the alginate oligosaccharide biosynthetic pathway proved by our previous study, UDP- d-glucose and dTDP- l-rhamnose biosynthetic pathways were identified. These might compete for glucose with the PHA biosynthesis. First, the alg operon, galU and rmlC gene were deleted one by one, resulting in NK-U-1(∆ alg), NK-U-2 (∆ alg∆ galU), NK-U-3( alg∆ galU∆ rmlC). After fermentation for 36 h, the cell dry weight (CDW) and PHA production of these strains were determined. Compared with NK-U: 1) NK-U-1 produced elevated CDW (from 3.19 ± 0.16 to 3.5 ± 0.11 g/l) and equal PHA (from 0.78 ± 0.06 to 0.79 ± 0.07 g/l); 2) NK-U-2 produced more CDW (from 3.19 ± 0.16 to 3.55 ± 0.23 g/l) and PHA (from 0.78 ± 0.06 to 1.05 ± 0.07 g/l); 3) CDW and PHA dramatically decreased in NK-U-3 (1.53 ± 0.21 and 0.41 ± 0.09 g/l, respectively). Additionally, the phaG gene was overexpressed in strain NK-U-2. Although CDW of NK-U-2/ phaG decreased to 1.29 ± 0.2 g/l, PHA titer (%CDW) significantly increased from 24.5 % up to 51.2 %. Conclusion: The PHA biosynthetic pathway was enhanced by blocking branched metabolic pathways in combination with overexpressing phaG gene. [ABSTRACT FROM AUTHOR]

Four methyl tert-butyl ether (MTBE)-degrading bacteria were isolated from a processing plant in Malaysia. Based on 16S rDNA sequences, the four isolates were identified as Exiguobacterium profundum P1M-2, Bacillus megaterium P1M-11, Alishewanella sp. P2A-12 and Pseudomonas mendocina P2M-8. Each of the isolates obtained optimum growth using a different source of nitrogen (0.1- 0.03 % yeast or peptone) and all four isolates were able to biodegrade 92.05-99.98 % of MTBE within seven days. Amongst the four isolates, the highest percentage of MTBE degradation was achieved using B. megaterium P1M-11. The highest growth on tert-butyl alcohol (TBA), tert-amyl alcohol (TAA) and 2-hydroxyisobutyric acid (2-HIBA) was also observed in B. megaterium P1M-11. This study suggests MTBE degradation by each of the bacteria can be enhanced by choosing the right nitrogen source. Furthermore, the ability of B. megaterium P1M-11 to grow on primary metabolites of MTBE and other structurally related ethers suggests the secretion of diverse degradative enzymes, making this isolate a good candidate to be applied in MTBE bioremediation strategies. [ABSTRACT FROM AUTHOR]