Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking
Microorganisms colonizing modern water-based metalworking fluids (MWFs) have been implicated in various occupational respiratory health hazards to machinists. An understanding of the exposure risks from specific microbial groups/genera/species (pathogenic or allergenic) and their endotoxins and the...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-01-01
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| Series: | Microorganisms |
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| Online Access: | https://www.mdpi.com/2076-2607/12/2/267 |
| _version_ | 1797297380899422208 |
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| author | Renuka Kapoor Suresh Babu Selvaraju Venkataramanan Subramanian Jagjit S. Yadav |
| author_facet | Renuka Kapoor Suresh Babu Selvaraju Venkataramanan Subramanian Jagjit S. Yadav |
| author_sort | Renuka Kapoor |
| collection | DOAJ |
| description | Microorganisms colonizing modern water-based metalworking fluids (MWFs) have been implicated in various occupational respiratory health hazards to machinists. An understanding of the exposure risks from specific microbial groups/genera/species (pathogenic or allergenic) and their endotoxins and the need for strategies for effective, timely fluid management warrant real-time extended tracking of the establishment of microbial diversity and the prevailing fluid-related factors. In the current study, the microbial community composition, succession, and dynamics of a freshly recharged industrial semi-synthetic MWF operation was tracked in real-time over a period of 50 weeks, using a combination of microbiological and molecular approaches. Substantial initial bacterial count (both viable and non-viable) even in the freshly recharged MWF pointed to the inefficiency of the dumping, cleaning, and recharge (DCR) process. Subsequent temporal analysis using optimized targeted genus/group-specific qPCR confirmed the presence of Pseudomonads, Enterics, Legionellae, Mycobacteria (<i>M. immunogenum</i>), Actinomycetes, and Fungi. In contrast, selective culturing using commercial culture media yielded non-specific isolates and collectively revealed Gram-negative (13 genera representing 19 isolates) and Gram-positive (2 genera representing 6 isolates) bacteria and fungi but not mycobacteria. <i>Citrobacter</i> sp. and <i>Bacillus cereus</i> represented the most frequent Gram-negative and Gram-positive isolates, respectively, across different media and <i>Nectria haematococca</i> isolation as the first evidence of this fungal pathogen colonizing semi-synthetic MWF. Unbiased PCR-DGGE analysis revealed a more diverse whole community composition revealing 22 bacterial phylotypes and their succession. Surges in the endotoxin level coincided with the spikes in Gram-negative bacterial population and biocide additions. Taken together, the results showed that semi-synthetic MWF is conducive for the growth of a highly diverse microbial community including potential bacterial and fungal pathogens, the current DCR practices are inefficient in combating microbial reestablishment, and the practice of periodic biocide additions facilitates the build-up of endotoxins and non-viable bacterial population. |
| first_indexed | 2024-03-07T22:20:33Z |
| format | Article |
| id | doaj.art-1df3809fb43a4f3088b29e9c6b227ea6 |
| institution | Directory Open Access Journal |
| issn | 2076-2607 |
| language | English |
| last_indexed | 2024-03-07T22:20:33Z |
| publishDate | 2024-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj.art-1df3809fb43a4f3088b29e9c6b227ea62024-02-23T15:28:02ZengMDPI AGMicroorganisms2076-26072024-01-0112226710.3390/microorganisms12020267Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time TrackingRenuka Kapoor0Suresh Babu Selvaraju1Venkataramanan Subramanian2Jagjit S. Yadav3Department of Environmental and Public Health Sciences, Division of Environmental Genetics and Molecular Toxicology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0056, USADepartment of Environmental and Public Health Sciences, Division of Environmental Genetics and Molecular Toxicology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0056, USADepartment of Environmental and Public Health Sciences, Division of Environmental Genetics and Molecular Toxicology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0056, USADepartment of Environmental and Public Health Sciences, Division of Environmental Genetics and Molecular Toxicology, University of Cincinnati College of Medicine, Cincinnati, OH 45267-0056, USAMicroorganisms colonizing modern water-based metalworking fluids (MWFs) have been implicated in various occupational respiratory health hazards to machinists. An understanding of the exposure risks from specific microbial groups/genera/species (pathogenic or allergenic) and their endotoxins and the need for strategies for effective, timely fluid management warrant real-time extended tracking of the establishment of microbial diversity and the prevailing fluid-related factors. In the current study, the microbial community composition, succession, and dynamics of a freshly recharged industrial semi-synthetic MWF operation was tracked in real-time over a period of 50 weeks, using a combination of microbiological and molecular approaches. Substantial initial bacterial count (both viable and non-viable) even in the freshly recharged MWF pointed to the inefficiency of the dumping, cleaning, and recharge (DCR) process. Subsequent temporal analysis using optimized targeted genus/group-specific qPCR confirmed the presence of Pseudomonads, Enterics, Legionellae, Mycobacteria (<i>M. immunogenum</i>), Actinomycetes, and Fungi. In contrast, selective culturing using commercial culture media yielded non-specific isolates and collectively revealed Gram-negative (13 genera representing 19 isolates) and Gram-positive (2 genera representing 6 isolates) bacteria and fungi but not mycobacteria. <i>Citrobacter</i> sp. and <i>Bacillus cereus</i> represented the most frequent Gram-negative and Gram-positive isolates, respectively, across different media and <i>Nectria haematococca</i> isolation as the first evidence of this fungal pathogen colonizing semi-synthetic MWF. Unbiased PCR-DGGE analysis revealed a more diverse whole community composition revealing 22 bacterial phylotypes and their succession. Surges in the endotoxin level coincided with the spikes in Gram-negative bacterial population and biocide additions. Taken together, the results showed that semi-synthetic MWF is conducive for the growth of a highly diverse microbial community including potential bacterial and fungal pathogens, the current DCR practices are inefficient in combating microbial reestablishment, and the practice of periodic biocide additions facilitates the build-up of endotoxins and non-viable bacterial population.https://www.mdpi.com/2076-2607/12/2/267semi-synthetic metalworking fluidmachining fluidmicrobial diversitymicrobial pathogensMycobacterium immunogenumendotoxin |
| spellingShingle | Renuka Kapoor Suresh Babu Selvaraju Venkataramanan Subramanian Jagjit S. Yadav Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking Microorganisms semi-synthetic metalworking fluid machining fluid microbial diversity microbial pathogens Mycobacterium immunogenum endotoxin |
| title | Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking |
| title_full | Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking |
| title_fullStr | Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking |
| title_full_unstemmed | Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking |
| title_short | Microbial Community Establishment, Succession, and Temporal Dynamics in an Industrial Semi-Synthetic Metalworking Fluid Operation: A 50-Week Real-Time Tracking |
| title_sort | microbial community establishment succession and temporal dynamics in an industrial semi synthetic metalworking fluid operation a 50 week real time tracking |
| topic | semi-synthetic metalworking fluid machining fluid microbial diversity microbial pathogens Mycobacterium immunogenum endotoxin |
| url | https://www.mdpi.com/2076-2607/12/2/267 |
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