1
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Mohamed SF, Narayanan R. Enterobacter cloacae-mediated polymer biodegradation: in-silico analysis predicts broad spectrum degradation potential by Alkane monooxygenase. Biodegradation 2024; 35:969-991. [PMID: 39001975 DOI: 10.1007/s10532-024-10091-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2024] [Accepted: 07/03/2024] [Indexed: 07/15/2024]
Abstract
Plastic pollution poses a significant environmental challenge. In this study, the strain Enterobacter cloacae O5-E, a bacterium displaying polyethylene-degrading capabilities was isolated. Over a span of 30 days, analytical techniques including x-ray diffractometry, scanning electron microscopy, optical profilometry, hardness testing and mass spectrometric analysis were employed to examine alterations in the polymer. Results revealed an 11.48% reduction in crystallinity, a 50% decrease in hardness, and a substantial 25-fold increase in surface roughness resulting from the pits and cracks introduced in the polymer by the isolate. Additionally, the presence of degradational by-products revealed via gas chromatography ascertains the steady progression of degradation. Further, recognizing the pivotal role of alkane monooxygenase in plastic degradation, the study expanded to detect this enzyme in the isolate molecularly. Molecular docking studies were conducted to assess the enzyme's affinity with various polymers, demonstrating notable binding capability with most polymers, especially with polyurethane (- 5.47 kcal/mol). These findings highlight the biodegradation potential of Enterobacter cloacae O5-E and the crucial involvement of alkane monooxygenase in the initial steps of the degradation process, offering a promising avenue to address the global plastic pollution crisis.
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Affiliation(s)
- Shafana Farveen Mohamed
- Department of Genetic Engineering, School of Bioengineering and Faculty of Engineering and Technology, College of Engineering & Technology (CET), SRM Institute of Science and Technology, Kattankulathur, Kanchipuram, Chennai, Tamil Nadu, 603203, India
| | - Rajnish Narayanan
- Department of Genetic Engineering, School of Bioengineering and Faculty of Engineering and Technology, College of Engineering & Technology (CET), SRM Institute of Science and Technology, Kattankulathur, Kanchipuram, Chennai, Tamil Nadu, 603203, India.
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2
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Sharma KK, Panwar H, Gupta KK. Isolation and characterization of bio-prospecting gut strains Bacillus safensis CGK192 and Bacillus australimaris CGK221 for plastic (HDPE) degradation. Biotechnol Lett 2024; 46:671-689. [PMID: 38705964 DOI: 10.1007/s10529-024-03486-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 12/20/2023] [Accepted: 03/10/2024] [Indexed: 05/07/2024]
Abstract
The present work reports the application of novel gut strains Bacillus safensis CGK192 (Accession No. OM658336) and Bacillus australimaris CGK221 (Accession No. OM658338) in the biological degradation of synthetic polymer i.e., high-density polyethylene (HDPE). The biodegradation assay based on polymer weight loss was conducted under laboratory conditions for a period of 90 days along with regular evaluation of bacterial biomass in terms of total protein content and viable cells (CFU/cm2). Notably, both strains achieved significant weight reduction for HDPE films without any physical or chemical pretreatment in comparison to control. Hydrophobicity and biosurfactant characterization were also done in order to assess strains ability to form bacterial biofilm over the polymer surface. The post-degradation characterization of HDPE was also performed to confirm degradation using analytical techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Field emission scanning electronic microscopy (FE-SEM) coupled with energy dispersive X-ray (EDX), and Gas chromatography-mass spectrometry (GC-MS). Interestingly strain CGK221 was found to be more efficient in forming biofilm over polymer surface as indicated by lower half-life (i.e., 0.00032 day-1) and higher carbonyl index in comparison to strain CGK192. The findings reflect the ability of our strains to develop biofilm and introduce an oxygenic functional group into the polymer surface, thereby making it more susceptible to degradation.
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Affiliation(s)
- Kamal Kant Sharma
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, India
| | - Himalaya Panwar
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, India
| | - Kartikey Kumar Gupta
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, India.
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3
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Mubayi V, Ahern CB, Calusinska M, O’Malley MA. Toward a Circular Bioeconomy: Designing Microbes and Polymers for Biodegradation. ACS Synth Biol 2024; 13:1978-1993. [PMID: 38918080 PMCID: PMC11264326 DOI: 10.1021/acssynbio.4c00077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 06/11/2024] [Accepted: 06/12/2024] [Indexed: 06/27/2024]
Abstract
Polymer production is rapidly increasing, but there are no large-scale technologies available to effectively mitigate the massive accumulation of these recalcitrant materials. One potential solution is the development of a carbon-neutral polymer life cycle, where microorganisms convert plant biomass to chemicals, which are used to synthesize biodegradable materials that ultimately contribute to the growth of new plants. Realizing a circular carbon life cycle requires the integration of knowledge across microbiology, bioengineering, materials science, and organic chemistry, which itself has hindered large-scale industrial advances. This review addresses the biodegradation status of common synthetic polymers, identifying novel microbes and enzymes capable of metabolizing these recalcitrant materials and engineering approaches to enhance their biodegradation pathways. Design considerations for the next generation of biodegradable polymers are also reviewed, and finally, opportunities to apply findings from lignocellulosic biodegradation to the design and biodegradation of similarly recalcitrant synthetic polymers are discussed.
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Affiliation(s)
- Vikram Mubayi
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Colleen B. Ahern
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
| | - Magdalena Calusinska
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Environmental
Research and Innovation Department, Luxembourg
Institute of Science and Technology, L-4422 Belvaux, Luxembourg
| | - Michelle A. O’Malley
- Department
of Chemical Engineering, University of California, Santa Barbara, California 93106, United States
- Department
of Bioengineering, University of California, Santa Barbara, California 93106, United States
- Joint
BioEnergy Institute (JBEI), Emeryville, California 94608, United States
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4
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Maheswaran B, Sebastin Raj J, Pandiyarajan P, Jaya Santhi R, Mythili R, K S V, Kim W, Karmegam N, Govarthanan M. Polyurethane degradation by extracellular urethanase producing bacterial isolate Moraxella catarrhalis strain BMPPS3. ENVIRONMENTAL RESEARCH 2024; 251:118631. [PMID: 38452914 DOI: 10.1016/j.envres.2024.118631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 02/08/2024] [Accepted: 03/04/2024] [Indexed: 03/09/2024]
Abstract
Plastic waste has become a global issue and a threat to the ecosystem. The present study isolated polyurethane (PU) degrading bacterial species from soil dumped with plastic wastes. Four bacterial isolates, RS1, RS6, RS9 and RS13 were obtained and their ability to degrade PU in a synthetic medium with PU as a sole source of carbon was assessed individually. After thirty days of incubation, the highest PU weight loss of 67.36 ± 0.32% was recorded in the medium containing RS13 isolate. The results of FTIR revealed the occurrence of carbonyl peaks. The putative isolate RS13 confirmed with the genus Moraxella according to 16S rRNA gene sequencing and the isolate was specified as Moraxella catarrhalis strain BMPPS3. The restriction analysis of Moraxella catarrhalis strain BMPPS3 revealed that the GCAT content to 51% and 49% correspondingly. Moraxella catarrhalis strain BMPPS3 was able to colonize on PU surface and form a biofilm as revealed by SEM investigation. Fatty acids and alkanes were found to be the degradation products by GC-MS analysis. The presence of these metabolites facilitated the growth of strain RS13 and suggested that ester hydrolysis products had been mineralized into CO2 and H2O. Extracellular biosurfactant synthesis has also been found in Moraxella catarrhalis strain BMPPS13 inoculated with synthetic media and mineral salt media containing PU and glucose as carbon sources, respectively with a significant level of cell-surface hydrophobicity (32%). The production and activity of extracellular esterase showed consistent increase from day 1-15 which peaked (1.029 mM/min/mg) on day 24 significantly at P < 0.001. Crude biosurfactants were lipopeptide-based, according to the characteristic investigation. According to this study findings, Moraxella catarrhalis produces biosurfactants of the esterase, urethanase and lipase (lipopeptide) types when carbon source PU is present.
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Affiliation(s)
- Baskaran Maheswaran
- Post Graduate Department of Biotechnology, Ayya Nadar Janaki Ammal College (Autonomous), Affiliated to Madurai Kamaraj University, Sivakasi, 626124, Tamil Nadu, India
| | - Joseph Sebastin Raj
- Post Graduate and Research Department of Biotechnology, Jamal Mohamed College (Autonomous), Affiliated to Bharathidasan University, Tiruchirappalli, 620020, Tamil Nadu, India.
| | - Pandiselvam Pandiyarajan
- Department of Computer Science and Engineering, School of Computing, Kalasalingam Academy of Research and Education, Krishnankoil, 626126, Tamil Nadu, India
| | - R Jaya Santhi
- Post Graduate and Research Department of Chemistry, Auxilium College (Autonomous), Affiliated to Thiruvalluvar University, Vellore, 632006, Tamil Nadu, India
| | - R Mythili
- Department of Pharmacology, Saveetha Dental College and Hospital, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, 600077, India
| | - Vignesh K S
- Centre for Occupational Safety and Health, Department of Mechanical Engineering, SRM Institute of Science and Technology, Chennai, 603203, Tamil Nadu, India
| | - Woong Kim
- Department of Environmental Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea
| | - N Karmegam
- PG and Research Department of Botany, Government Arts College (Autonomous), Salem, 636007, Tamil Nadu, India.
| | - Muthusamy Govarthanan
- Department of Environmental Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
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5
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Banerjee D, Patel C, Patel K. Degradation of Plastic Beads Containing Low Density Polyethylene (LDPE) by Sequential Photolysis, Hydrolysis and Bacterial Isolates. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2024; 112:41. [PMID: 38386139 DOI: 10.1007/s00128-024-03853-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Accepted: 01/04/2024] [Indexed: 02/23/2024]
Abstract
Plastic is an important part of today's human daily lifestyle, and it is classified as a "global pollutant" due to its durability. The natural degradation of plastic is extremely slow and will take a hundred years or more. The ultimate destinations of plastics as well as their effects on the ecosystem vary with the type of plastic and the rate of their degradation. In this study, an attempt was made to explain the degradation of low-density polyethylene (LDPE) plastic beads with the help of selected bacterial isolates in both laboratory and field conditions. 16 S rRNA gene sequencing further identified the bacterial isolates as Micrococcus luteus and Bacillus pumilus, obtained from the municipal waste disposal site near Anand, Gujarat, India. The beads were subjected to photolysis and hydrolysis for a predetermined amount of time in addition to biodegradation. After 60 days of treatment with Pseudomonas aeruginosa, Micrococcus luteus, and Bacillus pumilus in both laboratory and field conditions, a significant percentage decrease in the weight of LDPE beads was observed. Pseudomonas aeruginosa was taken as a positive control. Further, the rate of degradation was found to be accelerated in the presence of 10% starch.
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Affiliation(s)
- Devjani Banerjee
- Ashok and Rita Patel Institute Of Integrated Study and Research in Biotechnology & Allied Sciences (ARIBAS), New V V Nagar, Anand, India.
- GSFC University, Vigyan Bhavan, P.O. Fertilizer Nagar, Vadodara, Gujarat, 391750, India.
| | - Chandani Patel
- Ashok and Rita Patel Institute Of Integrated Study and Research in Biotechnology & Allied Sciences (ARIBAS), New V V Nagar, Anand, India
| | - Kajal Patel
- Ashok and Rita Patel Institute Of Integrated Study and Research in Biotechnology & Allied Sciences (ARIBAS), New V V Nagar, Anand, India
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6
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Rong Z, Ding ZH, Wu YH, Xu XW. Degradation of low-density polyethylene by the bacterium Rhodococcus sp. C-2 isolated from seawater. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 907:167993. [PMID: 37866604 DOI: 10.1016/j.scitotenv.2023.167993] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/04/2023] [Accepted: 10/19/2023] [Indexed: 10/24/2023]
Abstract
Low-density polyethylene (LDPE), which accounts for 20% of the global plastic production, is discharged in great quantities into the ocean, threatening marine life and ecosystems. Marine microorganisms have previously been reported to degrade LDPE plastics; however, the exploration of strains and enzymes that degrade LDPE is still limited. Here, an LDPE-degrading bacterium was isolated from seawater of the Changjiang Estuary, China and identified as Rhodococcus sp. C-2, the relative abundance of which was dramatically enhanced during PE-degrading microbial enrichment. The strain C-2 exhibited the degradation of LDPE films, leading to their morphological deterioration, reduced hydrophobicity and tensile strength, weight loss, as well as the formation of oxygen-containing functional groups in short-chain products. Sixteen bacterial enzymes potentially involved in LDPE degradation were screened using genomic, transcriptomic, and degradation product analyses. Thereinto, the glutathione peroxidase GPx with exposed active sites catalyzed the LDPE depolymerization with the cooperation of its dissociated superoxide anion radicals. Furthermore, an LDPE degradation model involving multiple enzymes was proposed. The present study identifies a novel PE-degrading enzyme (PEase) for polyethylene bioremediation and promotes the understanding of LDPE degradation.
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Affiliation(s)
- Zhen Rong
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, PR China; Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, PR China
| | - Zhi-Hao Ding
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, PR China; Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, PR China
| | - Yue-Hong Wu
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, PR China; Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, PR China.
| | - Xue-Wei Xu
- School of Oceanography, Shanghai Jiao Tong University, Shanghai 200240, PR China; Key Laboratory of Marine Ecosystem Dynamics, Ministry of Natural Resources & Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou 310012, PR China.
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7
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Akash K, Parthasarathi R, Elango R, Bragadeeswaran S. Characterization of Priestia megaterium S1, a polymer degrading gut microbe isolated from the gut of Tenebrio molitor larvae fed on Styrofoam. Arch Microbiol 2023; 206:48. [PMID: 38160211 DOI: 10.1007/s00203-023-03785-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Revised: 11/18/2023] [Accepted: 12/03/2023] [Indexed: 01/03/2024]
Abstract
This study reveals that Tenebrio molitor larvae are fed with two different feeds i.e., barley bran along with Styrofoam, and barley bran without Styrofoam, the survival percentage of mealworms shows 86 and 89%, respectively. Five isolates namely S1, S2, S3, S4, and S5 were isolated from the gut of Styrofoam-feeding Tenebrio molitor larvae and tested for Hydrophobicity percentage, clear zone assay and turbidity measurement. S1 isolate showed best (turbidity percentage of 19.65%, 13.54% hydrophobicity percentage, and 37% zone of clearance) when compared to other isolates, respectively. 16S rRNA characterization of S1 isolate revealed that the isolate belongs to Priestia megaterium S1(ON024787). Biodegradation of PE and PS beads by Priestia megaterium S1 makes physical and structural changes over 180 days, after microbial adhesion to the beads. Growth parameters have shown that the Priestia megaterium S1 thrives more effectively in the pH (6.5), temperature (28 °C) and at 1.5% LDPE/HDPE/PS concentration there is maximum utilization of carbon and a high percentage survival rate. Significant colonization of the isolate after 30 days over beads of LDPE (52.47%), HDPE (49.26%), and PS (48.11%), respectively. Experimental data revealed that Priestia megaterium S1 have PE and PS beads degradation capacity, proven by weight loss studies, at 6th-month percentage weight loss of LDPE (36.1%), HDPE (31.9%), and PS (28.6%), the percentage loss of carbon and hydrogen shows higher when compared to control. One month Biological Oxygen Demand (BOD) showed that LDPE (7.4 mg/l), HDPE (7.2 mg/l), PS (6.7 mg/l), and simultaneous studies on CO2 evolution over LDPE treatment is 5.05 g/l, HDPE (4.26 g/l), and PS (3.91 g/l), respectively. Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscope (SEM) prove the occurrence of biodegradation on the surface of beads. This work highlights that Priestia megaterium S1 plays a vital role in effectively degrading PE and PS beads.
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Affiliation(s)
- Krishnamoorthi Akash
- Department of Microbiology, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Chidambaram, Tamilnadu, 608002, India
| | - Rengasamy Parthasarathi
- Department of Microbiology, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Chidambaram, Tamilnadu, 608002, India.
- Department of Soil Science and Agricultural Chemistry, Anbil Dharmalingam Agricultural College and Research Institute, Trichy, Tamilnadu, 620027, India.
| | - Rajavel Elango
- Department of Microbiology, Faculty of Agriculture, Annamalai University, Annamalai Nagar, Chidambaram, Tamilnadu, 608002, India
| | - Subramanian Bragadeeswaran
- Centre for Advanced Study in Marine Biology, Faculty of Marine Sciences, Annamalai University, Parangipettai, Tamilnadu, 608505, India
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8
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Devi D, Gupta KK, Chandra H, Sharma KK, Sagar K, Mori E, de Farias PAM, Coutinho HDM, Mishra AP. Biodegradation of low-density polyethylene (LDPE) through application of indigenous strain Alcaligenes faecalis ISJ128. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2023; 45:9391-9409. [PMID: 37184721 DOI: 10.1007/s10653-023-01590-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Accepted: 04/18/2023] [Indexed: 05/16/2023]
Abstract
The resiliency of plastic products against microbial degradation in natural environment often creates devastating changes for humans, plants, and animals on the earth's surface. Biodegradation of plastics using indigenous bacteria may serve as a critical approach to overcome this resulting environmental stress. In the present work, a polyethylene degrading bacterium Alcaligenes faecalis strain ISJ128 (Accession No. MK968769) was isolated from partially degraded polyethylene film buried in the soil at plastic waste disposal site. The biodegradation studies were conducted by employing various methods such as hydrophobicity assessment of the strain ISJ128, measurement of viability and total protein content of bacterial biofilm attached to the polyethylene surface. The proliferation of bacterial cells on polyethylene film, as indicated by high growth response in terms of protein content (85.50 µg mL-1) and viability (1010 CFU mL-1), proposed reasonable suitability of our strain A. faecalis ISJ128 toward polyethylene degradation. The results of biodegradation assay revealed significant degradation (10.40%) of polyethylene film within a short period of time (i.e., 60 days), whereas no signs of degradation were seen in control PE film. A. faecalis strain ISJ128 also demonstrated a removal rate of 0.0018 day-1 along with half-life of 462 days. The scanning electron microscope (SEM) and Fourier transform infrared (FTIR) spectroscopy studies not only displayed changes on polyethylene surface but also altered level of intensity of functional groups and an increase in the carbonyl indexes justifying the degradation of polyethylene film due to bacterial activity. In addition, the secondary structure prediction (M fold software) of 16SrDNA proved the stable nature of the bacterial strain, thereby reflecting the profound scope of A. faecalis strain ISJ128 as a potential degrader for the eco-friendly disposal of polyethylene waste. Schematic representation of methodology.
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Affiliation(s)
- Deepa Devi
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, 249404, India
| | - Kartikey Kumar Gupta
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, 249404, India.
| | - Harish Chandra
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, 249404, India
| | - Kamal Kant Sharma
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, 249404, India
| | - Kalpana Sagar
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Haridwar, Uttarakhand, 249404, India
| | - Edna Mori
- CECAPE College, Av. Padre Cícero, 3917 - São José, Juazeiro do Norte, CE, 63024-015, Brazil
| | | | - Henrique Douglas Melo Coutinho
- Department of Chemical Biology, Regional University of Cariri - URCA, Av. Cel Antonio Luiz, 1161, Pimenta, Crato, CE, 63105-000, Brazil.
| | - Abhay Prakash Mishra
- Department of Pharmacology, University of Free State, Bloemfontein, 9300, Free State, South Africa.
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9
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Rojas-Vargas J, Castelán-Sánchez HG, Pardo-López L. HADEG: A curated hydrocarbon aerobic degradation enzymes and genes database. Comput Biol Chem 2023; 107:107966. [PMID: 37778093 DOI: 10.1016/j.compbiolchem.2023.107966] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Revised: 09/25/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023]
Abstract
Databases of genes and enzymes involved in hydrocarbon degradation have been previously reported. However, these databases specialize on only a specific group of hydrocarbons and/or are constructed partly based on enzyme sequences with putative functions indicated by in silico research, with no experimental evidence. Here, we present a curated database of Hydrocarbon Aerobic Degradation Enzymes and Genes (HADEG) containing proteins and genes involved in alkane, alkene, aromatic, and plastic aerobic degradation and biosurfactant production based solely on experimental evidence, which are present in bacteria, and fungi. HADEG includes 259 proteins for petroleum hydrocarbon degradation, 160 for plastic degradation, and 32 for biosurfactant production. This database will help identify and predict hydrocarbon degradation genes/pathways and biosurfactant production in genomes.
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Affiliation(s)
- Jorge Rojas-Vargas
- Departamento de Microbiología Molecular, Instituto de Biotecnología, UNAM, Av. Universidad #2001, Col. Chamilpa, 62210 Cuernavaca, Morelos, Mexico.
| | - Hugo G Castelán-Sánchez
- Programa de Investigadoras e Investigadores por México, Grupo de Genómica y Dinámica Evolutiva de Microorganismos Emergentes, Consejo Nacional de Ciencia y Tecnología, Av. Insurgentes Sur 1582, Crédito Constructor, Benito Juárez, CP 03940 Ciudad de México, Mexico
| | - Liliana Pardo-López
- Departamento de Microbiología Molecular, Instituto de Biotecnología, UNAM, Av. Universidad #2001, Col. Chamilpa, 62210 Cuernavaca, Morelos, Mexico.
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10
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Qiang L, Hu H, Li G, Xu J, Cheng J, Wang J, Zhang R. Plastic mulching, and occurrence, incorporation, degradation, and impacts of polyethylene microplastics in agroecosystems. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 263:115274. [PMID: 37499389 DOI: 10.1016/j.ecoenv.2023.115274] [Citation(s) in RCA: 15] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 07/29/2023]
Abstract
Polyethylene microplastics have been detected in farmland soil, irrigation water, and soil organisms in agroecosystems, while plastic mulching is suggested as a crucial source of microplastic pollution in the agroecosystem. Plastic mulch can be broken down from plastic mulch debris to microplastics through environmental aging and degradation process in farmlands, and the colonization of polyethylene-degrading microorganisms on polyethylene microplastics can eventually enzymatically depolymerize the polyethylene molecular chains with CO2 release through the tricarboxylic acid cycle. The selective colonization of microplastics by soil microorganisms can cause changes in soil microbial community composition, and it can consequently elicit changes in enzyme activities and nutrient element content in the soil. The biological uptake of polyethylene microplastics and the associated disturbance of energy investment are the main mechanisms impacting soil-dwelling animal development and behavior. As polyethylene microplastics are highly hydrophobic, their presence among soil particles can contribute to soil water repellency and influence soil water availability. Polyethylene microplastics have been shown to cause impacts on crop plant growth, as manifested by the effects of polyethylene microplastics on soil properties and soil biota in the agroecosystems. This review reveals the degradation process, biological impacts, and associated mechanisms of polyethylene microplastics in agroecosystems and could be a critical reference for their risk assessment and management.
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Affiliation(s)
- Liyuan Qiang
- College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China; Key Laboratory of Northwest Agricultural Equipment, Ministry of Agriculture and Rural Affairs, Xinjiang 832003, China
| | - Huibing Hu
- College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China; Key Laboratory of Northwest Agricultural Equipment, Ministry of Agriculture and Rural Affairs, Xinjiang 832003, China
| | - Guoqiang Li
- College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China; Key Laboratory of Northwest Agricultural Equipment, Ministry of Agriculture and Rural Affairs, Xinjiang 832003, China
| | - Jianlong Xu
- College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China; Key Laboratory of Northwest Agricultural Equipment, Ministry of Agriculture and Rural Affairs, Xinjiang 832003, China
| | - Jinping Cheng
- Department of Science and Environmental Studies, The Education University of Hong Kong, New Territories, Hong Kong SAR, China; The Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China.
| | - Jiaping Wang
- Agricultural College, Shihezi University, Shihezi, Xinjiang 832003, China
| | - Ruoyu Zhang
- College of Mechanical and Electrical Engineering, Shihezi University, Shihezi, Xinjiang 832003, China; Key Laboratory of Northwest Agricultural Equipment, Ministry of Agriculture and Rural Affairs, Xinjiang 832003, China.
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11
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Jayan N, Skariyachan S, Sebastian D. The escalated potential of the novel isolate Bacillus cereus NJD1 for effective biodegradation of LDPE films without pre-treatment. JOURNAL OF HAZARDOUS MATERIALS 2023; 455:131623. [PMID: 37207482 DOI: 10.1016/j.jhazmat.2023.131623] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 05/10/2023] [Accepted: 05/11/2023] [Indexed: 05/21/2023]
Abstract
This study focused on the biodegradation of LDPE films using a novel isolate of Bacillus obtained from soil samples collected from a 20-year-old plastic waste dump. The aim was to evaluate the biodegradability of LDPE films treated with this bacterial isolate. The results indicated a 43% weight loss of LDPE films within 120 days of treatment. The biodegradability of LDPE films was confirmed through various testing methods, including BATH, FDA, CO2 evolution tests, and changes in total cell growth count, protein content, viability, pH of the medium, and release of microplastics. The bacterial enzymes, including laccases, lipases, and proteases, were also identified. SEM analysis revealed biofilm formation and surface changes in treated LDPE films, while EDAX analysis showed a reduction in carbon elements. AFM analysis demonstrated differences in roughness compared to the control. Furthermore, wettability increased and tensile strength decreased, confirming the biodegradation of the isolate. FTIR spectral analysis showed changes in skeletal vibrations, such as stretches and bends, in the linear structure of polyethylene. FTIR imaging and GC-MS analysis also confirmed the biodegradation of LDPE films by the novel isolate identified as Bacillus cereus strain NJD1. The study highlights the potentiality of the bacterial isolate for safe and effective microbial remediation of LDPE films.
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Affiliation(s)
- Nithya Jayan
- Department of Life Sciences, University of Calicut, Malappuram, Kerala 673635, India
| | - Sinosh Skariyachan
- St. Pius X College Rajapuram, Department of Microbiology, Kasaragod, India
| | - Denoj Sebastian
- Department of Life Sciences, University of Calicut, Malappuram, Kerala 673635, India.
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Mamtimin T, Han H, Khan A, Feng P, Zhang Q, Ma X, Fang Y, Liu P, Kulshrestha S, Shigaki T, Li X. Gut microbiome of mealworms (Tenebrio molitor Larvae) show similar responses to polystyrene and corn straw diets. MICROBIOME 2023; 11:98. [PMID: 37147715 PMCID: PMC10161430 DOI: 10.1186/s40168-023-01550-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 04/16/2023] [Indexed: 05/07/2023]
Abstract
BACKGROUND Some insects can degrade both natural and synthetic plastic polymers, their host and gut microbes play crucial roles in this process. However, there is still a scientific gap in understanding how the insect adapted to the polystyrene (PS) diet from natural feed. In this study, we analyzed diet consumption, gut microbiota responses, and metabolic pathways of Tenebrio molitor larvae exposed to PS and corn straw (CS). RESULTS T. molitor larvae were incubated under controlled conditions (25 ± 1 °C, 75 ± 5% humidity) for 30 days by using PS foam with weight-, number-, and size-average molecular weight (Mw, Mn, and Mz) of 120.0, 73.2, and 150.7 kDa as a diet, respectively. The larvae exhibited lower PS consumption (32.5%) than CS (52.0%), and these diets had no adverse effects on their survival. The gut microbiota structures, metabolic pathways, and enzymatic profiles of PS- and CS-fed larvae showed similar responses. The gut microbiota of larvae analysis indicated Serratia sp., Staphylococcus sp., and Rhodococcus sp. were associated with both PS and CS diets. Metatranscriptomic analysis revealed that xenobiotics, aromatic compounds, and fatty acid degradation pathways were enriched in PS- and CS-fed groups; laccase-like multicopper oxidases, cytochrome P450, monooxygenase, superoxidase, and dehydrogenase were involved in lignin and PS degradation. Furthermore, the upregulated gene lac640 in both PS- and CS-fed groups was overexpressed in E. coli and exhibited PS and lignin degradation ability. CONCLUSIONS The high similarity of gut microbiomes adapted to biodegradation of PS and CS indicated the plastics-degrading ability of the T. molitor larvae originated through an ancient mechanism that degrades the natural lignocellulose. Video Abstract.
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Affiliation(s)
- Tursunay Mamtimin
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Huawen Han
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China.
- State Key Laboratory of Grassland Agro-Ecosystems, Center for Grassland Microbiome, Lanzhou University, Lanzhou, China.
| | - Aman Khan
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Pengya Feng
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Qing Zhang
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Xiaobiao Ma
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Yitian Fang
- State Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Pu Liu
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China
| | - Saurabh Kulshrestha
- Faculty of Applied Sciences and Biotechnology, Shoolini University, Solan, India
| | - Toshiro Shigaki
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Xiangkai Li
- Ministry of Education Key Laboratory of Cell Activities and Stress Adaptations, School of Life Science, Lanzhou University, Lanzhou, China.
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Salinas J, Carpena V, Martínez-Gallardo MR, Segado M, Estrella-González MJ, Toribio AJ, Jurado MM, López-González JA, Suárez-Estrella F, López MJ. Development of plastic-degrading microbial consortia by induced selection in microcosms. Front Microbiol 2023; 14:1143769. [PMID: 37113240 PMCID: PMC10126402 DOI: 10.3389/fmicb.2023.1143769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 03/16/2023] [Indexed: 04/29/2023] Open
Abstract
The increase in the production of highly recalcitrant plastic materials, and their accumulation in ecosystems, generates the need to investigate new sustainable strategies to reduce this type of pollution. Based on recent works, the use of microbial consortia could contribute to improving plastic biodegradation performance. This work deals with the selection and characterization of plastic-degrading microbial consortia using a sequential and induced enrichment technique from artificially contaminated microcosms. The microcosm consisted of a soil sample in which LLDPE (linear low-density polyethylene) was buried. Consortia were obtained from the initial sample by sequential enrichment in a culture medium with LLDPE-type plastic material (in film or powder format) as the sole carbon source. Enrichment cultures were incubated for 105 days with monthly transfer to fresh medium. The abundance and diversity of total bacteria and fungi were monitored. Like LLDPE, lignin is a very complex polymer, so its biodegradation is closely linked to that of some recalcitrant plastics. For this reason, counting of ligninolytic microorganisms from the different enrichments was also performed. Additionally, the consortium members were isolated, molecularly identified and enzymatically characterized. The results revealed a loss of microbial diversity at each culture transfer at the end of the induced selection process. The consortium selected from selective enrichment in cultures with LLDPE in powder form was more effective compared to the consortium selected in cultures with LLDPE in film form, resulting in a reduction of microplastic weight between 2.5 and 5.5%. Some members of the consortia showed a wide range of enzymatic activities related to the degradation of recalcitrant plastic polymers, with Pseudomonas aeruginosa REBP5 or Pseudomonas alloputida REBP7 strains standing out. The strains identified as Castellaniella denitrificans REBF6 and Debaryomyces hansenii RELF8 were also considered relevant members of the consortia although they showed more discrete enzymatic profiles. Other consortium members could collaborate in the prior degradation of additives accompanying the LLDPE polymer, facilitating the subsequent access of other real degraders of the plastic structure. Although preliminary, the microbial consortia selected in this work contribute to the current knowledge of the degradation of recalcitrant plastics of anthropogenic origin accumulated in natural environments.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Francisca Suárez-Estrella
- Unit of Microbiology, Department of Biology and Geology, CITE II-B, Agrifood Campus of International Excellence ceiA3, CIAIMBITAL, University of Almeria, Almeria, Spain
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Gupta KK, Sharma KK, Chandra H. Utilization of Bacillus cereus strain CGK5 associated with cow feces in the degradation of commercially available high-density polyethylene (HDPE). Arch Microbiol 2023; 205:101. [PMID: 36862211 DOI: 10.1007/s00203-023-03448-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/13/2022] [Accepted: 02/21/2023] [Indexed: 03/03/2023]
Abstract
The accumulation and mismanagement of high-density polyethylene (HDPE) waste in the environment is a complex problem in the present scenario. Biodegradation of this thermoplastic polymer is a promising environmentally sustainable method that offers a significant opportunity to address plastic waste management with minimal negative repercussion on the environment. In this framework, HDPE-degrading bacterium strain CGK5 was isolated from the fecal matter of cow. The biodegradation efficiency of strain was assessed, including percentage reduction in HDPE weight, cell surface hydrophobicity, extracellular biosurfactant production, viability of surface adhered cells, as well as biomass in terms of protein content. Through molecular techniques, strain CGK5 was identified as Bacillus cereus. Significant weight loss of 1.83% was observed in the HDPE film treated with strain CGK5 for 90 days. The FE-SEM analysis revealed the profused bacterial growth which ultimately caused the distortions in HDPE films. Furthermore, EDX study indicated a significant decrease in percentage carbon content at atomic level, whereas FTIR analysis confirmed chemical groups' transformation as well as an increment in the carbonyl index supposedly caused by bacterial biofilm biodegradation. Our findings shed light on the ability of our strain B. cereus CGK5 to colonize and use HDPE as a sole carbon source, demonstrating its applicability for future eco-friendly biodegradation processes.
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Affiliation(s)
- Kartikey Kumar Gupta
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Uttarakhand, Haridwar, India
| | - Kamal Kant Sharma
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Uttarakhand, Haridwar, India.
| | - Harish Chandra
- Department of Botany and Microbiology, Gurukula Kangri (Deemed to be University), Uttarakhand, Haridwar, India
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Zhang C, Mu Y, Li T, Jin FJ, Jin CZ, Oh HM, Lee HG, Jin L. Assembly strategies for polyethylene-degrading microbial consortia based on the combination of omics tools and the "Plastisphere". Front Microbiol 2023; 14:1181967. [PMID: 37138608 PMCID: PMC10150012 DOI: 10.3389/fmicb.2023.1181967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 03/31/2023] [Indexed: 05/05/2023] Open
Abstract
Numerous microorganisms and other invertebrates that are able to degrade polyethylene (PE) have been reported. However, studies on PE biodegradation are still limited due to its extreme stability and the lack of explicit insights into the mechanisms and efficient enzymes involved in its metabolism by microorganisms. In this review, current studies of PE biodegradation, including the fundamental stages, important microorganisms and enzymes, and functional microbial consortia, were examined. Considering the bottlenecks in the construction of PE-degrading consortia, a combination of top-down and bottom-up approaches is proposed to identify the mechanisms and metabolites of PE degradation, related enzymes, and efficient synthetic microbial consortia. In addition, the exploration of the plastisphere based on omics tools is proposed as a future principal research direction for the construction of synthetic microbial consortia for PE degradation. Combining chemical and biological upcycling processes for PE waste could be widely applied in various fields to promote a sustainable environment.
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Affiliation(s)
- Chengxiao Zhang
- College of Biology and the Environment, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Yulin Mu
- College of Biology and the Environment, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Taihua Li
- College of Biology and the Environment, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Feng-Jie Jin
- College of Biology and the Environment, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
| | - Chun-Zhi Jin
- Cell Factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea
| | - Hee-Mock Oh
- Cell Factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea
| | - Hyung-Gwan Lee
- Cell Factory Research Centre, Korea Research Institute of Bioscience & Biotechnology, Daejeon, Republic of Korea
- Hyung-Gwan Lee,
| | - Long Jin
- College of Biology and the Environment, Co-Innovation Centre for Sustainable Forestry in Southern China, Nanjing Forestry University, Nanjing, China
- *Correspondence: Long Jin,
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Maheswaran B, Al-Ansari M, Al-Humaid L, Sebastin Raj J, Kim W, Karmegam N, Mohamed Rafi K. In vivo degradation of polyethylene terephthalate using microbial isolates from plastic polluted environment. CHEMOSPHERE 2023; 310:136757. [PMID: 36228720 DOI: 10.1016/j.chemosphere.2022.136757] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 09/23/2022] [Accepted: 10/02/2022] [Indexed: 06/16/2023]
Abstract
Accumulation of plastics alarms a risk to the environment worldwide. As polyethylene pterephthalate (PET) degrades slowly and produces hazardous substances, therefore, it is now essential to eliminate plastic wastes from the environment. Given that, the current study is concerned with PET degradation potential of naturally occurring microbial strains isolated from plastic waste dumping sites, Sarcina aurantiaca (TB3), Bacillus subtilis (TB8), Aspergillus flavus (STF1), Aspergillus niger (STF2). To test the biodegradability of PET films, the films were incubated for 60 days at 37 °C with the microorganisms designated as TB3, TB8, STF1, STF2 and the microbial consortium (TB3+TB8+STF1+STF2) in Minimal Salt Medium and Bushnell Hass Broth. Hydrophobicity, viability, and total protein content of isolates were investigated. Using Field Emission Scanning Electron Microscopy and Fourier Transform Infrared Spectrophotometry to measure variations in functional groups and carbonyl index on PET surface, biodegradation process was affirmed by fissures and modified surfaces. Results revealed that the microbial consortium (S. aurantiaca + B. subtilis + A. flavus + A. niger) that the weight loss of PET films was 28.78%. The microbial consortium could be used to treat PET waste, posing no health or environmental risks. The developed microbial consortium has the potential to degrade PET, hence can be employed for eliminating PET in plastic contaminated sites.
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Affiliation(s)
- Baskaran Maheswaran
- Post Graduate and Research Department of Biotechnology, Jamal Mohamed College (Autonomous), Affiliated to Bharathidasan University, Tiruchirappalli, 620 020, Tamil Nadu, India
| | - Mysoon Al-Ansari
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Latifah Al-Humaid
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Joseph Sebastin Raj
- Post Graduate and Research Department of Biotechnology, Jamal Mohamed College (Autonomous), Affiliated to Bharathidasan University, Tiruchirappalli, 620 020, Tamil Nadu, India.
| | - Woong Kim
- Department of Environmental Engineering, Kyungpook National University, Daegu, 41566, Republic of Korea.
| | - Natchimuthu Karmegam
- PG and Research Department of Botany, Government Arts College (Autonomous), Salem, 636 007, Tamil Nadu, India.
| | - Kasim Mohamed Rafi
- Post Graduate and Research Department of Botany, Jamal Mohamed College (Autonomous), Affiliated to Bharathidasan University, Tiruchirappalli, 620 020, Tamil Nadu, India
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Micrococcus luteus strain CGK112 isolated from cow dung demonstrated efficient biofilm-forming ability and degradation potential toward high-density polyethylene (HDPE). Arch Microbiol 2022; 204:402. [PMID: 35718788 DOI: 10.1007/s00203-022-03023-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Accepted: 05/29/2022] [Indexed: 11/02/2022]
Abstract
Biodegradation is the most promising environmentally sustainable method that offers a significant opportunity with minimal negative environmental consequences while searching for solutions to this global problem of plastic pollution that has now spread to almost everywhere in the entire world. In the present work, HDPE-degrading bacterial strain CGK112 was isolated from the fecal matter of a cow. The bacterial strain was identified as Micrococcus luteus CGK112 by 16S rRNA sequence coding analysis. Significant weight loss, i.e., 3.85% was recorded in the HDPE film treated with strain CGK112 for 90 days. The surface micromorphology was examined using FE-SEM, which revealed spectacular bacterial colonization as well as structural deformation. Furthermore, the EDX study indicated a significant decrease in the atomic percentage of carbon content, whereas FTIR analysis confirmed functional groups alternation as well as an increase in the carbonyl index which can be attributed to the metabolic activity of biofilm. Our findings provide insight into the capacity of our strain CGK112 to colonize and utilize HDPE as a single carbon source, thus promoting its degradation.
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Barcoto MO, Rodrigues A. Lessons From Insect Fungiculture: From Microbial Ecology to Plastics Degradation. Front Microbiol 2022; 13:812143. [PMID: 35685924 PMCID: PMC9171207 DOI: 10.3389/fmicb.2022.812143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 03/15/2022] [Indexed: 11/13/2022] Open
Abstract
Anthropogenic activities have extensively transformed the biosphere by extracting and disposing of resources, crossing boundaries of planetary threat while causing a global crisis of waste overload. Despite fundamental differences regarding structure and recalcitrance, lignocellulose and plastic polymers share physical-chemical properties to some extent, that include carbon skeletons with similar chemical bonds, hydrophobic properties, amorphous and crystalline regions. Microbial strategies for metabolizing recalcitrant polymers have been selected and optimized through evolution, thus understanding natural processes for lignocellulose modification could aid the challenge of dealing with the recalcitrant human-made polymers spread worldwide. We propose to look for inspiration in the charismatic fungal-growing insects to understand multipartite degradation of plant polymers. Independently evolved in diverse insect lineages, fungiculture embraces passive or active fungal cultivation for food, protection, and structural purposes. We consider there is much to learn from these symbioses, in special from the community-level degradation of recalcitrant biomass and defensive metabolites. Microbial plant-degrading systems at the core of insect fungicultures could be promising candidates for degrading synthetic plastics. Here, we first compare the degradation of lignocellulose and plastic polymers, with emphasis in the overlapping microbial players and enzymatic activities between these processes. Second, we review the literature on diverse insect fungiculture systems, focusing on features that, while supporting insects' ecology and evolution, could also be applied in biotechnological processes. Third, taking lessons from these microbial communities, we suggest multidisciplinary strategies to identify microbial degraders, degrading enzymes and pathways, as well as microbial interactions and interdependencies. Spanning from multiomics to spectroscopy, microscopy, stable isotopes probing, enrichment microcosmos, and synthetic communities, these strategies would allow for a systemic understanding of the fungiculture ecology, driving to application possibilities. Detailing how the metabolic landscape is entangled to achieve ecological success could inspire sustainable efforts for mitigating the current environmental crisis.
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Affiliation(s)
- Mariana O. Barcoto
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, Brazil
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
| | - Andre Rodrigues
- Center for the Study of Social Insects, São Paulo State University (UNESP), Rio Claro, Brazil
- Department of General and Applied Biology, São Paulo State University (UNESP), Rio Claro, Brazil
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