To date, the genus Parvularcula consists of 6 species and no potential application of this genus was reported. Current study presents the genome sequence of Parvularcula flava strain NH6-79 T and its cellulolytic enzyme analysis. The assembled draft genome of strain NH6-79 T consists of 9 contigs and 7 scaffolds with 3.68 Mbp in size and GC content of 59.87%. From a total of 3,465 genes predicted, 96 of them are annotated as glycoside hydrolases (GHs). Within these GHs, 20 encoded genes are related to cellulosic biomass degradation, including 12 endoglucanases (5 GH10, 4 GH5, and 3 GH51), 2 exoglucanases (GH9) and 6 β-glucosidases (GH3). In addition, highest relative enzyme activities (endoglucanase, exoglucanase, and β-glucosidase) were observed at 27th hour when the strain was cultured in the carboxymethyl cellulose/Avicel®-containing medium for 45 h. The combination of genome analysis with experimental studies indicated the ability of strain NH6-79 T to produce extracellular endoglucanase, exoglucanase, and β-glucosidase. These findings suggest the potential of Parvularcula flava strain NH6-79 T in cellulose-containing biomass degradation and that the strain could be used in cellulosic biorefining process.
Wastewater monitoring for SARS-CoV-2 has attracted considerable attention worldwide to complement the existing clinical-based surveillance system. In this study, we report our first successful attempt to prove the circulation of SARS-CoV-2 genes in Malaysian urban wastewater. A total of 18 wastewater samples were obtained from a regional sewage treatment plant that received municipal sewage between February 2021 and May 2021. Using the quantitative PCR assay targeting the E and RdRp genes of SARS-CoV-2, we confirmed that both genes were detected in the raw sewage, while no viral RNA was found in the treated sewage. We were also able to show that the trend of COVID-19 cases in Kuala Lumpur and Selangor was related to the changes in SARS-CoV-2 RNA levels in the wastewater samples. Overall, our study highlights that monitoring wastewater for SARS-CoV-2 should help local health professionals to obtain additional information on the rapid and silent circulation of infectious agents in communities at the regional level.
The coloured effluents produced from different industries, such as textile, plastics, printing, cosmetics, leather and paper, are extremely toxic and a tremendous threat to the aquatic organisms and human beings. The removal of coloured dye pollutants from the aqueous environment is a great challenge and a pressing task. The growing demand for low-cost and efficient treatment approaches has given rise to alternative and eco-friendly methods, such as biodegradation and microbial remediation. This work summarizes the overview and current research on the remediation of dye pollutants from the aqueous environment by microbial bio-sorbents, such as bacteria, fungi, algae, and yeast. In addition, dye degradation capabilities of microbial enzymes have been highlighted and discussed. Further, the influence of various experimental parameters, such as temperature, pH, and concentrations of nutrients, and dye, has been summarized. The proposed mechanism for dye removal by microorganisms is also discussed. The object of this review is to provide a state-of-the-art of microbial remediation technologies in eliminating dye pollutants from water resources.
The emergence and transmission of antibiotic resistance is a global public health crisis with significant burden on healthcare systems, resulting in high mortality and economic costs. In 2019, almost five million deaths were associated with drug-resistant infections, and if left unchecked, the global economy could lose $100 trillion by 2050. To effectively combat this crisis, it is essential for all countries to understand the current situation of antibiotic resistance. In this review, we examine the current driving factors leading to the crisis, impact of critical superbugs in three regions, and identify novel mechanisms of antibiotic resistance. It is crucial to monitor the phenotypic characteristics of drug-resistant pathogens and describe the mechanisms involved in preventing the emergence of cross-resistance to novel antimicrobials. Additionally, maintaining an active pipeline of new antibiotics is essential for fighting against diverse antibiotic-resistant pathogens. Developing antibacterial agents with novel mechanisms of action is a promising way to combat increasing antibiotic-resistant pathogens.
Nepenthes pitcher plants produce modified jug-shaped leaves to attract, trap and digest insect prey. We used 16S rDNA cloning and sequencing to compare bacterial communities in pitcher fluids of each of three species, namely Nepenthes ampullaria, Nepenthes gracilis and Nepenthes mirabilis, growing in the wild. In contrast to previous greenhouse-based studies, we found that both opened and unopened pitchers harbored bacterial DNA. Pitchers of N. mirabilis had higher bacterial diversity as compared to other Nepenthes species. The composition of the bacterial communities could be different between pitcher types for N. mirabilis (ANOSIM: R = 0.340, p < 0.05). Other Nepenthes species had similar bacterial composition between pitcher types. SIMPER showed that more than 50 % of the bacterial taxa identified from the open pitchers of N. mirabilis were not found in other groups. Our study suggests that bacteria in N. mirabilis are divided into native and nonnative groups.
In this study, a total of 147 soil actinobacterial strains were screened for their ability to inhibit response of Chromobacterium violaceum CV026 to short chain N-acyl homoserine lactone (AHL) which is a quorum sensing molecule. Of these, three actinobacterial strains showed positive for violacein inhibition. We further tested these strains for the inhibition of Pseudomonas aeruginosa PAO1 quorum sensing-regulated phenotypes, namely, swarming and pyocyanin production. The three strains were found to inhibit at least one of the quorum sensing-regulated phenotypes of PAO1. Phylogenetic analysis of the 16S rRNA gene sequences indicated that these strains belong to the genera Micromonospora, Rhodococcus and Streptomyces. This is the first report presenting quorum quenching activity by a species of the genus Micromonospora. Our data suggest that Actinobacteria may be a rich source of active compounds that can act against bacterial quorum sensing system.
A Gram-staining-negative, aerobic, rod-shaped, yellow-orange-pigmented, gliding bacterium, designated as strain ST2L12(T), was isolated from estuarine mangrove sediment from Matang Mangrove Forest, Perak, Malaysia. Strain ST2L12(T) grew at 15-39 °C, pH 6-8 and in 1-6 % (w/v) NaCl. This strain was able to degrade xylan and casein. 16S rRNA gene sequence analysis showed 95.3-92.8 % similarity to members of the genera Mangrovimonas, Meridianimaribacter, Sediminibacter, Gaetbulibacter and Hoppeia. Phylogenetic analysis indicated that it belonged to the family Flavobacteriaceae. Respiratory quinone present was menaquinone-6 (MK-6), and the DNA G+C content was 38.3 mol%. The predominant fatty acids were iso-C15:0, iso-C15:1, C15:0 and iso-C17:0 3-OH. Moreover, previous genome comparison study showed that the genome of ST2L12(T) is 1.4 times larger compared to its closest relative, Mangrovimonas yunxiaonensis LYYY01(T). Phenotypic, fatty acid, 16S rRNA gene sequence and previous genome data indicate that strain ST2L12(T) represents a novel species of the genus Mangrovimonas in the family Flavobacteriaceae, for which the name Mangrovimonas xylaniphaga sp. nov. is proposed. The type strain of Mangrovimonas xylaniphaga is ST2L12(T) (=LMG 28914(T)=JCM 30880(T)).
Producing recombinant proteins is a major accomplishment of biotechnology in the past century. Heterologous hosts, either eukaryotic or prokaryotic, are used for the production of these proteins. The utilization of microbial host systems continues to dominate as the most efficient and affordable method for biotherapeutics and food industry productions. Hence, it is crucial to analyze the limitations and advantages of microbial hosts to enhance the efficient production of recombinant proteins on a large scale. E. coli is widely used as a host for the production of recombinant proteins. Researchers have identified certain obstacles with this host, and given the growing demand for recombinant protein production, there is an immediate requirement to enhance this host. The following review discusses the elements contributing to the manifestation of recombinant protein. Subsequently, it sheds light on innovative approaches aimed at improving the expression of recombinant protein. Lastly, it delves into the obstacles and optimization methods associated with translation, mentioning both cis-optimization and trans-optimization, producing soluble recombinant protein, and engineering the metal ion transportation. In this context, a comprehensive description of the distinct features will be provided, and this knowledge could potentially enhance the expression of recombinant proteins in E. coli.
The influence of light exposure on antioxidant and antimicrobial activities of nine fungal isolates [Pseudopestalotiopsis theae (EF13), Fusarium solani (EF5), Xylaria venustula (PH22), Fusarium proliferatum (CCH), Colletotrichum boninese (PL9), Colletotrichum boninese (PL1), Colletotrichum boninese (OL2), Colletotrichum gloeosporioides (OL3) and Colletotrichum siamense (PL3)] were determined. The isolates were incubated in blue, red, green, yellow and white fluorescent light (12 h photoperiod of alternating light/dark). It was observed that green light induced higher total phenolic content (TPC) (2.96 ± 0.16 mg-30.71 ± 1.03 mg GAE/g) and ferric reducing antioxidant power (FRAP) in most isolates (4.82 ± 0.04-53.55 ± 4.33 mg GAE/g), whereas red light induced higher total flavonoid content (TFC) levels (1.14 ± 0.08-18.40 ± 1.12 mg QE/g). The crude extracts from most fungal cultures exposed to green and red lights were also notably more potent against the tested pathogens, as larger zones of inhibition (ZOI) (9.00 ± 1.00-38.30 ± 2.90 mm) and lower minimum inhibitory concentration (MIC) (0.0196-1.25 mg/mL) were achieved for antimicrobial effect. This study showed that light treatments are effective strategies in enhancing production of more potent antimicrobial compounds and valuable antioxidants from fungal isolates.
Bioremediation of heavy metals and dyes is one of the emerging techniques globally as it is evident from the numerous publications made by various research groups. Biofilm-assisted bioremediation is one of the trending approaches as it facilitates negatively charged extracellular polymeric substances which makes the bacteria resistant to the toxic chemicals. Genetic engineering of microbes will make them unique in the bioremediation process. This mini-review concentrates on source and toxic effects of heavy metals and dyes on aqueous and living beings. Further, the genetic improvement strategies for effective bioremediation are described. However, the gap between practicability and real-time applicability needs to test with real-time wastewater in the industrial scale.
Infections by ESKAPE (Enterococcus sp., Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) pathogens cause major concern due to their multi-drug resistance (MDR). The ESKAPE pathogens are frequently linked to greater mortality, diseases, and economic burden in healthcare worldwide. Therefore, the use of plants as a natural source of antimicrobial agents provide a solution as they are easily available and safe to use. These natural drugs can also be enhanced by incorporating silver nanoparticles and combining them with existing antibiotics. By focussing the attention on the ESKAPE organisms, the MDR issue can be addressed much better.
Microbial diversity within formation water and oil from two compartments in Bokor oil reservoir from a Malaysian petroleum oil field was examined. A total of 1,056 16S rRNA gene clones were screened from each location by amplified ribosomal DNA restriction analysis. All samples were dominated by clones affiliated with Marinobacter, some novel Deferribacteraceae genera and various clones allied to the Methanococci. In addition, either Marinobacterium- or Pseudomonas-like operational taxonomic units were detected from either compartment. A systematic comparison with the existing pertinent studies was undertaken by analysing the microbial amplicons detected and the PCR primers used. The analyses demonstrated that bacterial communities were site specific, while Archaea co-occurred more frequently. Amplicons related to Marinobacter, Marinobacterium and Pseudomonas were detected in a number of the studies examined, suggesting they may be ubiquitous members in oil reservoirs. Further analysis of primers used in those studies suggested that most primer pairs had fairly broad but low matches across the bacterial and archaeal domains, while a minority had selective matches to certain taxa or low matches to all the microbial taxa tested. Thus, it indicated that primers may play an important role in determining which taxa would be detected.
The continuous rise of antimicrobial resistance (AMR) is a serious concern as it endangers the effectiveness of healthcare interventions that rely on antibiotics in the long run. The increasing resistance of Neisseria gonorrhoeae, the bacteria responsible for causing gonorrhea, to commonly used antimicrobial drugs, is a major concern. This has now become a critical global health crisis. In the coming years, there is a risk of a hidden epidemic caused by the emergence of gonococcal AMR. This will worsen the global situation. Infections caused by N. gonorrhoeae were once considered easily treatable. However, over time, they have become increasingly resistant to commonly used therapeutic medications, such as penicillin, ciprofloxacin, and azithromycin. As a result, this pathogen is developing into a true "superbug," which means that ceftriaxone is now the only available option for initial empirical treatment. Effective management strategies are urgently needed to prevent severe consequences, such as infertility and pelvic inflammatory disease, which can result from delayed intervention. This review provides a thorough analysis of the escalating problem of N. gonorrhoeae, including its pathogenesis, current treatment options, the emergence of drug-resistant mechanisms, and the potential for vaccine development. We aim to provide valuable insights for healthcare practitioners, policymakers, and researchers in their efforts to combat N. gonorrhoeae antibiotic resistance by elucidating the multifaceted aspects of this global challenge.
Quorum sensing (QS) is a term used to describe cell-to-cell communication that enables bacteria to orchestrate group behaviours according to density of bacterial cells. In Gram-negative bacteria, this signalling system is widely known to regulate a variety of different phenotypes such as antibiotic production and biofilm formation. In this study, we report the production of N-acyl homoserine lactones produced by Chromobacterium haemolyticum strain KM2, a bacterium isolated from a river water of a reserved tropical national park. Preliminary screening of QS activity using biosensor reporter assays indicated that C. haemolyticum strain KM2 produces both short- and long-chain AHLs. Analysis with high-resolution liquid chromatography-mass spectrometry (LC-MS/MS) analysis revealed the production of three AHLs by strain KM2: N-octanoyl-L-homoserine lactone (C8-HSL), N-dodecanoyl-L-homoserine lactone (C12-HSL), and N-3-oxo-dodecanoyl-L-homoserine lactone (OC12-HSL). This bacterial isolate also exhibited strong β-haemolytic activity. To the best of our knowledge, this is the first documentation of QS activity and multiple AHLs production by C. haemolyticum strain KM2.
Waxy crude oil is a problem to the oil and gas industry because wax deposition in pipelines reduces the quality of the crude oil. Currently, the industry uses chemicals to solve the problem but it is not environmentally friendly. As an alternative, the biodegradation approach is one of the options. Previously eleven thermophilic bacteria were isolated and exhibited high ability to degrade hydrocarbon up to 70% of waxy crude oil. However, despite the successful study on these single bacteria strains, it is believed that biodegradation of paraffin wax requires more than a single species. Five consortia were developed based on the biodegradation efficiency of 11 bacterial strains. Consortium 3 showed the highest biodegradation (77.77%) with more long-chain alkane degraded throughout the incubation compared to other consortia. Enhancement of hydrocarbon degradation was observed for all consortia especially in long chain alkane (C18-C40). Consortium 3 exhibited higher alkane monooxygenase, alcohol dehydrogenase, lipase, and esterase activities. Moreover, the dominant bacteria in the consortia were determined by denaturing gradient gel electrophoresis (DGGE), which showed the domination of genera Geobacillus, Parageobacillus, and Anoxybacillus. It can be concluded that the bacterial consortia showed higher biodegradation and improved degrading more long-chain hydrocarbon compared to a single isolate.
Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly effects immunocompromised individuals, and a sight threatening keratitis, known as Acanthamoeba keratitis, which mostly affects contact lens wearers. The current treatment available is problematic, and is toxic. Herein, an amphiphilic star polymer with AB2 miktoarms [A = hydrophobic poly(ℇ-Caprolacton) and B = hydrophilic poly (ethylene glycol)] was synthesized by ring opening polymerization and CuI catalyzed azide-alkyne cycloaddition. Characterization by 1H and 13C NMR spectroscopy, size-exclusion chromatography and fluorescence spectroscopy was accomplished. The hydrophobic drug itraconazole (ITZ) was incorporated in self-assembled micellar structure of AB2 miktoarms through co-solvent evaporation. The properties of ITZ loaded (ITZ-PCL-PEG2) and blank micelles (PCL-PEG2) were investigated through zeta sizer, scanning electron microscopy and Fourier-transform infrared spectroscopy. Itraconazole alone (ITZ), polymer (DPB-PCL), empty polymeric micelles (PCL-PEG2) alone, and itraconazole loaded in polymeric micelles (ITZ-PCL-PEG2) were tested for anti-amoebic potential against Acanthamoeba, and the cytotoxicity on human cells were determined. The polymer was able to self-assemble in aqueous conditions and exhibited low value for critical micelle concentration (CMC) 0.05-0.06 µg/mL. The maximum entrapment efficiency of ITZ was 68%. Of note, ITZ, DPB, PCL-PEG2 and ITZ-PCL-PEG2 inhibited amoebae trophozoites by 37.34%, 36.30%, 35.77%, and 68.24%, respectively, as compared to controls. Moreover, ITZ-PCL-PEG2 revealed limited cytotoxicity against human keratinocyte cells. These results are indicative that ITZ-PCL-PEG2 micelle show significantly better anti-amoebic effects as compared to ITZ alone and thus should be investigated further in vivo to determine its clinical potential.
This work investigates the effect of heterocyst toward biohydrogen production by A. variabilis. The heterocyst frequency was artificially promoted by adding an amino acid analog, in this case DL-7-azatryptophan into the growth medium. The frequency of heterocyst differentiation was found to be proportional to the concentration of azatryptophan (0-25 µM) in the medium. Conversely, the growth and nitrogenase activity were gradually suppressed. In addition, there was also a distinct shortening of the cells filaments and detachment of heterocyst from the vegetative cells. Analysis on the hydrogen production performance revealed that both the frequency and distribution of heterocyst in the filaments affected the rate of hydrogen production. The highest hydrogen production rate and yield (41 µmol H2 mg chl a(-1) h(-1) and 97 mL H2 mg chl a(-1), respectively) were achieved by cells previously grown in 15 µM of azatryptophan with 14.5 % of heterocyst frequency. The existence of more isolated heterocyst has been shown to cause a relative loss in nitrogenase activity thus lowering the hydrogen production rate.
The human immunodeficiency virus (HIV) is a type of lentivirus that targets the human immune system and leads to acquired immunodeficiency syndrome (AIDS) at a later stage. Up to 2021, there are millions still living with HIV and many have lost their lives. To date, many anti-HIV compounds have been discovered in living organisms, especially plants and marine sponges. However, no treatment can offer a complete cure, but only suppressing it with a life-long medication, known as combined antiretroviral therapy (cART) or highly active antiretroviral therapy (HAART) which are often associated with various adverse effects. Also, it takes many years for a discovered compound to be approved for clinical use. Thus, by employing advanced technologies such as automation, conducting systematic screening and testing protocols may boost the discovery and development of potent and curative therapeutics for HIV infection/AIDS. In this review, we aim to summarize the antiretroviral therapies/compounds and their associated drawbacks since the discovery of azidothymidine. Additionally, we aim to provide an updated analysis of the most recent discoveries of promising antiretroviral candidates, along with an exploration of the current limitations within antiretroviral research. Finally, we intend to glean insightful perspectives and propose future research directions in this crucial area of study.
Biodegradation is an eco-friendly measure to address plastic pollution. This study screened four bacterial isolates that were capable of degrading recalcitrant polymers, i.e., low-density polyethylene, polyethylene terephthalate, and polystyrene. The unique bacterial isolates were obtained from plastic polluted environment. Dermacoccus sp. MR5 (accession no. OP592184) and Corynebacterium sp. MR10 (accession no. OP536169) from Malaysian mangroves and Bacillus sp. BS5 (accession no. OP536168) and Priestia sp. TL1 (accession no. OP536170) from a sanitary landfill. The four isolates showed a gradual increase in the microbial count and the production of laccase and esterase enzymes after 4 weeks of incubation with the polymers (independent experiment set). Bacillus sp. BS5 produced the highest laccase 15.35 ± 0.19 U/mL and showed the highest weight loss i.e., 4.84 ± 0.6% for PS. Fourier transform infrared spectroscopy analysis confirmed the formation of carbonyl and hydroxyl groups as a result of oxidation reactions by enzymes. Liquid chromatography-mass spectrometry analysis showed the oxidation of the polymers to small molecules (alcohol, ethers, and acids) assimilated by the microbes during the degradation. Field emission scanning electron microscopy showed bacterial colonization, biofilm formation, and surface erosion on the polymer surface. The result provided significant insight into enzyme activities and the potential of isolates to target more than one type of polymer for degradation.
Lumpy skin disease (LSD) is a highly infectious and economically devastating viral disease of cattle. It is caused by Lumpy Skin Disease Virus (LSDV) belonging to the genus Capripoxvirus and family Poxviridae. The origin of lumpy skin disease has been traced to Zambia, (an African nation) in Southern part during the year 1929. The first reported case of LSD besides Africa was from Israel, a Middle Eastern nation, thus proving inter-continental spread. Subsequently, the disease entered Middle East, Eastern Europe and Asia with numerous outbreaks in the recent years. LSD has emerged as a significant concern in the Indian sub-continent, due to outbreaks reported in countries such as Bangladesh, India, China in 2019. In the following years, other South and East Asian countries like Taipei, Nepal, Sri Lanka, Myanmar, Bhutan, Vietnam, Hong Kong, Thailand, Malaysia, Laos, Cambodia, Pakistan, Indonesia and Singapore also faced severe outbreaks. At present, LSD is considered to be an emerging disease in the Indian sub-continent due to the recent status of disease. Considering the global scenario, LSDV is changing its transmission dynamics as evidenced by a shift in its epidemiology. As a result of high morbidity and mortality rate among cattle, the current outbreaks have been a major cause of socio-economic catastrophe. This contagious viral disease has eminent repercussions as the estimated monetary damage incurred is quite high. Despite having networked surveillance and comprehensive databases, the recurring outbreaks have raised major concern among researchers. Therefore, this review offers brief insights into the emergence of LSDV by amalgamating the newest literature related to its biology, transmission, clinico-pathology, epidemiology, prevention strategies, and economic consequences. Additionally, we have also provided the epidemiological insights of the recent outbreaks with detailed state wise studies.