Specifically for fiber use, problems hinge around issues of scale and economy, in which the retting and decortication process has been described as a “bottleneck” for supplying consistent product to industry manufacturers [, This work, together with past and recent studies of bast fiber retting, indicate that hemp (as well as other common bast fiber plants) harbor a resilient cohort of microorganisms that appear to be present at harvest and continue to persist throughout the retting process. Received: 5 March 2020 / Revised: 25 March 2020 / Accepted: 27 March 2020 / Published: 1 April 2020, (This article belongs to the Special Issue, Presently, synthetic fibers dominate the market when it comes to industrial applications [, The 2014 US Farm Bill allowed state departments of agriculture to approve hemp pilot programs for farmers, colleges, and universities. ; Baxter, N.T. 12. ; Westcott, S.L. A six inch section was removed from the center of each stalk and cut into 1 cm pieces which were processed with a paddle blender (Bag Mixer 400, Interscience) using BagPage XR filter bags at high speed and closest setting for 5 min in 150 mL 100 mM sodium phosphate buffer, pH 7.0. ; White, K.H. ; Tittes, S.B. MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Classical field retting and controlled fungal retting of hemp using Phlebia radiata Cel 26 (a mutant with low cellulose degrading ability) were compared with pure pectinase treatment with regard to mechanical properties of the produced fibre/epoxy composites. Please note that many of the page functionalities won't work as expected without javascript enabled. Our dedicated information section provides allows you to learn more about MDPI. Endophytes are likely to be present in relatively low abundances at the time of harvest, and while significant patterns among the low abundance microorganisms were not detected, their contribution to the retting process cannot be discounted, as they are already “on-site” within the stalk when the plant is cut and the degradation begins. This experiment was conducted in order to learn how the microbial population responds to environmental conditions such as moisture variability and soil exposure, but controlled within a greenhouse rather than variable conditions in the field. The cut stalks were prepared for retting in the greenhouse by measuring the total length of each stalk and cutting a 4 ft (73.44 cm) section from the center before placing in constructed retting boxes. ; Rigsby, L.L. �̶!S��������k�+��E.�k�����1���D��p��;1�bzr�����\���[����k��j��ud�����z�����6mZ[�)+�O��t�� �0}����ڝus���x$&��@:rj��{�,)�ϒ'!�|�1;es�ĚW@���[�]�?�^$�����r� �?�Q��][�O�E� ; writing—original draft preparation, A.D.L. Waste retting water, which requires treatment to reduce harmful toxic elements before its release, is rich in chemicals and can be used as liquid fertilizer. Clostridium butylicum) are involved in the retting of fibres of coconut, jute, flax, hemp etc. You seem to have javascript disabled. Amaducci, S.; Zatta, A.; Pelatti, F.; Venturi, G. Influence of agronomic factors on yield and quality of hemp (Cannabis sativa L.) fibre and implication for an innovative production system. ; Feng, X.X. Schellenberger, S.; Kolb, S.; Drake, H.L. Bacillus, Lactobacillus, Pediococcus and Leuconostoc are effective bacterial sources for fermentation processes that produce pectinolytic enzymes. ; Huttenhower, C. Metagenomic biomarker discovery and explanation. Dew retting tends to yield a dark-colored fiber. (2011). and C.R.M. Each frame represented a treatment, and each section within the frame contained 21 stalks of an individual variety. Henriksson, G.; Akin, D.E. The retting box consisted of three wooden frames (3 m × 1.5 m), separated into three equal sections (3.33 m), which were set on benches in the greenhouse and overlaid with 4 mil plastic, with 4 layers of burlap lining the bottom of each section. At T3, the LM treatment was significantly lower than HM for measures Shannon diversity, and at T6 the LM treatment was lower for observed richness as well as Shannon diversity compared to the HM treatment (, A total of 20 Phyla were present in the dataset; the most abundant were Proteobacteria (85.55%), Bacteroidetes, (7.58%), Bacteria_unclassified (2.78%), Actinobacteria (2.27%), and Firmicutes (1.13%), with Deinococcus-Thermus, Verrucomicrobia, Planctomycetes, Acidobacteria, candidate_division_WPS-1, Armatimonadetes, Candidatus_Saccharibacteria, Gemmatimonadetes, Fusobacteria, Chloroflexi, Tenericutes, Chlamydiae, SR1, candidate_division_WPS-2, and Nitrospirae making up the remaining 0.71%. During retting, microbial activity degrades polysaccharides, mainly pectin, that bind the bast fibers to the hurd core such that they can be separated by a mechanical process called decortication [. Cannabis Domestication, Breeding History, Present-day Genetic Diversity, and Future Prospects. This study, along with previous research, looks to the microbial population as a means to manipulate and/or control the retting process, with the intent to provide a cost effective means to increase consistency of the product. %PDF-1.6 %���� Within each variety, all treatments compared at each time point and over time, showed no significant differences in alpha diversity measures and ANOSIM analysis (not shown). The plants are immersed in water and when they swell, inoculated with bacteria which hydrolyze pectic substances of the cell walls and separate the fibres. Fundamentals of Microbial Community Resistance and Resilience. Ribeiro, A.; Pochart, P.; Day, A.; Mennuni, S.; Bono, P.; Baret, J.-L.; Spadoni, J.-L.; Mangin, I. Microbial diversity observed during hemp retting. ; Baho, D.L. These bacteria primarily decompose the plant pectin thus, freeing the fibres. Flint, H.J. Esty, W.W. Retting is a biological process by which the bast fibres are extracted by decomposing the plants by the combined action of water and aquatic microorganisms, mostly bacteria. It involves microbial decomposition of the unwanted material. The various factors involved have been separated in an attempt to intensify certain ones in order to make the process shorter, and also to produce a better fiber. Subscribe to receive issue release notifications and newsletters from MDPI journals, You can make submissions to other journals. Industrial Hemp: Renewed Opportunities for an Ancient Crop. Information about how these factors affect the microbial population involved in the retting process and whether or not it differs by variety can lead to improvements in the quality and value of field-retted hemp, thereby increasing profitability for farmers and encouraging the inclusion of more natural fibers in industry and manufacturing. ; et al. Name any two plant disease caused by the bacteria … The statements, opinions and data contained in the journal, © 1996-2021 MDPI (Basel, Switzerland) unless otherwise stated. Find support for a specific problem on the support section of our website. Fibre are extracted by retting methods, viz. Effect of harvest time and field retting duration on the chemical composition, morphology and mechanical properties of hemp fibers. Cherney, J.H. and L.A.M. However, it is far less labor intensive and less expensive than water retting. ; Scott, K.P. However, numerous factors have reported influences on mechanical properties of the fibre-reinforced composite, including natural fibre retting processes. ; Parks, D.H.; Robinson, C.J. ; Louis, P.; Forano, E. Microbial degradation of complex carbohydrates in the gut. ; data curation, A.D.L. Kozich, J.J.; Westcott, S.L. The tensile strength and chemical composition of kenaf fiber showed large variability for every location collected and for each processing technique used. It is used in the production of fibre from plant materials such as flax and hemp stalks and coir from coconut husks. However, their applications are limited since manufacturers have some difficulties to standardise fabrication processes. RESULTS Ofthe different sporeformingaerobic bacteria identi- fied as Bacilluspolyrnyxa,Bacillus subtilis, Bacillus cereus, Bacillus sphaericus, Bacillus lentus, andBacilluts pumilus,the only bacterium found to ret jute was Bacillus polymyxa. Field retting is the most common method used by western countries, as it … Three varieties were chosen for the study, two common fiber varieties, Futura 75 and Felina 32, and SS Alpha, an experimental variety that is being tested for its suitability for fiber crops in the US. ; Hanlin, R.T.; Rodriguez, C.; Archibald, D.D. • The microorganisms, mostly bacteria from retting water enter the plant tissues through the stomata, epidermis and cambium or the cut end, when immersed in retting tank, and through their enzymatic action loosens the fibre strands from the woody core. Retting process is used for obtaining fibres from stems of flax, hemp, jute etc. This bacterium wasisolated from a … Clostridium butyricum is used in the process and these bacteria hydrolyze the middle lamella of these plant fibres. ; Eriksson, K.L. Liu, M.; Ale, M.T. Commercial fiber is separated in the fiber yielding plants by the decomposition of non-cellulosic cementing material through a process called retting. For field retting a classification of the microbial evolution (by gene sequencing) and enzyme profiles were conducted. Retting is indeed a natural process, and may be regarded as merely a step in the cycles of the elements. Dufrêne, M.; Legendre, P. Species Assemblages and Indicator Species: The Need for a Flexible Asymmetrical Approach. While specific OTUs did not show strong associations in ISA or LeFse analysis by treatment, the HM and SHM samples showed a significant increase in the abundance of the phylum, Our results indicate that a resilient microbial community associated with the plant stalks at harvest remained throughout the retting process and changed little according to the treatments applied and over the five weeks it took to ret the stalks completely. Example:Jute is associated with the process of … Comparison of traditional field retting and Phlebia radiata Cel 26 retting of hemp fibres for fibre-reinforced composites. hemp microbiome; fiber crops; fiber retting, Help us to further improve by taking part in this short 5 minute survey, Arbuscular Mycorrhizal Fungi Associated with Rice (, Present Status and Perspective on the Future Use of Aflatoxin Biocontrol Products, Drivers of Microbial Diversity and Roles in Agroecosystems, http://microbe.med.umich.edu/services/microbial-community-analysis, http://creativecommons.org/licenses/by/4.0/. The LM treatment consisted of 200 mL autoclaved deionized water misted over stalks every day using a surface sterilized hand-held sprayer. 11. Retting of Fibers • Bacteria (e.g. ; Koti, S.; Linga, V.R. Fibre retting Bacterial populations, especially that of Clostridium butyclicum, are used to separate fibres of jute, hemp, flax, etc, the plants are immersed in water and when they swell, inoculated with bacteria which hydrolyze pectic substance of the cell walls and separate the fibres.These separated fibres are used to make ropes and sacks. Kenaf fiber was separated by the water retting method, where the combination of water retting and mechanical retting was based on the available facilities and proficiency at the sites. The fibres from the fibre yielding plants are separated by the action of Closiridium is called retting of fibres. ; Highlander, S.K. Author to whom correspondence should be addressed. This is distinct from the process of water retting, used mainly for textile quality fibers, in which the stalks are submerged in water which may contain additional enzymes and/or microbial cultures . ; Chen, J.M. ; et al. Djemiel, C.; Grec, S.; Hawkins, S. Characterization of Bacterial and Fungal Community Dynamics by High-Throughput Sequencing (HTS) Metabarcoding during Flax Dew-Retting. Schluttenhofer, C.; Yuan, L. Challenges towards Revitalizing Hemp: A Multifaceted Crop. It is commonly used … and L.A.M. Retting is a process employing the action of micro-organisms and moisture on plants to dissolve or rot away much of the cellular tissues and pectins surrounding bast-fibre bundles, and so facilitating separation of the fibre from the stem. For this purpose, stems of fibre yielding plants are immersed in water for a long period where decomposition sets in. For this purpose, stems of fibre yielding plants are immersed in water for long period where decomposition sets in. Mandolino, G.; Carboni, A. Metabolic responses of novel cellulolytic and saccharolytic agricultural soil Bacteria to oxygen. Field retting is the most practical method of hemp fiber production for farmers in the US, but little research has been done on the microbiota associated with hemp stalks during field retting, or on applied practices that improve the quality and consistency of the fiber without substantially increasing cost. Department of Plant and Soil Sciences, University of Kentucky, Lexington, KY 40546, USA, Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, KY 40546, USA. The authors declare no conflict of interest. All authors have read and agreed to the published version of the manuscript. �_�$��*������iG�d[N��M��J3.�,8p�R�m٫�? Characterization and biological depectinization of hemp fibers originating from different stem sections. Retting and degumming of natural fibers by pectinolytic enzymes produced from Bacillus tequilensis SV11-UV37 using solid state fermentation. Fortenbery, T.R. Additionally, 1 L of water was used to wet the burlap (avoiding stalks) every other day to simulate moisture retained in the soil in a field environment. funding acquisition, L.A.M. Question 60. ; Chen, J.Y. The water, penetrating to the central stalk portion, swells the inner cells, bursting the outermost layer, thus increasing absorption of both moisture and decay-producing bacteria. Results were analyzed based on knowledge of the cell wall active enzymes produced by the two fungi. “Review of bast fiber retting,” BioResources 6(4), 5260-5281. Shade, A.; Peter, H.; Allison, S.D. Leather industry (Tannery): • In leather industry, removal of hairs, fats and other tissues from raw hide is done by bacteria. ; Merlin, M.D. The LM treatment, which received the least amount of water during retting, resulted in significant differences compared to HM and SHM, including lower richness and evenness at T6 and ANOSIM community similarity comparisons showing increasing R-values over time. • The fibres are then mechanically extracted, washed, dried and marketed. Buffer filtered from the plant debris was poured into 250 mL sterile centrifuge bottles and centrifuged at 10,000×, DNA from hemp and soil samples was shipped to The University of Michigan Microbial Systems Molecular Biology Laboratory core sequencing facility (, Sequence data from MiSeq analysis was processed using Mothur software (v1.40.5) following the MiSeq SOP (, Statistical analysis was performed using programs in Mothur [, The three varieties (FE, FU, SSa) were compared at each time point. Chiliveri, S.R. ; Schloss, P.D. This study is a first step before selection and isolation of strains that could later be used to optimise microbial retting efficiency and hence fibre quality. Conceptualization, A.D.L., C.R.M. We would like to acknowledge the contributions of Patrick Perry and the late David Williams for their expert advice and permission for use plants from the UK variety trials. chemical, water, microbes and microbe-chemical retting. ; methodology, A.D.L. Enhanced retting was observed in stems sprayed with B. subtilis and consequently the stems produced finer fibres than fibres from E. carotovora-sprayed or control stems. Then mechanically extracted, washed, dried and marketed saccharolytic agricultural soil to. ; Yuan, L. Challenges towards Revitalizing hemp: a Multifaceted Crop retting is indeed a natural process, Future. 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