scholarly journals Characterization of substrates of growing media by Fourier transform infrared (FT-IR) spectroscopy for containerized crop production

2021 ◽  
Vol 13 (SI) ◽  
pp. 35-42
Author(s):  
N. Elakiya ◽  
K. Arulmozhiselvan

Growing media used in soilless culture systems are those solid substrates, which alone or in mixtures can guarantee better plant growth conditions similar to agricultural soil in one or many aspects. This study was aimed to characterize lignocellulosic organic substances predominant in most available and effective organic substrates viz., coir pith and dhaincha (Sesbania aculeata) powder and compost maturity in vermicompost based on the presence of functional groups by Fourier transform infrared (FT-IR) spectroscopy. The dominant downward peaks noted at 3300-3500 cm-1 in coir pith and dhaincha indicate vibration of hydroxyl (OH­-) stretch in cellulose structure and presence of alcohols and phenols. Peaks at 2925-2850 cm-1 found prominently in coirpith would be indicative of vibration of C-H bonds showing aliphatic degradation of cellulose, hemicelluloses, lipids, fats, etc. Particularly in dhaincha, vibration at 1733.32 cm-1 would be due to C=O stretch associated with an unconjugated ketone, carbonyl and ester groups. In vermicompost, peak value around 1549.85 cm-1 indicates C=C aromatic structure formed during mineralization of protein, cellulose, and hemicelluloses showing compost maturity. In the present study, FT-IR analysis of organic lignocellulosic substrates confirmed the occurrence of lignin, hemicellulose and cellulose, which are the main characteristics of natural fibers with high water holding and cation exchange capacity. Presence of alcoholic and carboxylic groups indicated stages of compost maturity and stability. Therefore, these renewable and environmentally sustainable lignocellulosic organic materials could be recognized as ideal soilless substrates for preparing grow media for containerized crop production and also recycling organic wastes in an environmentally friendly manner.  

2020 ◽  
Author(s):  
Huayan Yang ◽  
Fangling Wu ◽  
Fuxin Xu ◽  
Keqi Tang ◽  
Chuanfan Ding ◽  
...  

Abstract Fourier transform infrared (FT-IR) spectroscopy is a label-free and highly sensitive technique that provides complete information on the chemical composition of biological samples. The bacterial FT-IR signals are extremely specific and highly reproducible fingerprint-like patterns, making FT-IR an efficient tool for bacterial typing and identification. Due to the low cost and high flux, FT-IR has been widely used in hospital hygiene management for infection control, epidemiological studies, and routine bacterial determination of clinical laboratory values. However, the typing and identification accuracy could be affected by many factors, and the bacterial FT-IR data from different laboratories are usually not comparable. A standard protocol is required to improve the accuracy of FT-IR-based typing and identification. Here, we detail the principles and procedures of bacterial typing and identification based on FT-IR spectroscopy, including bacterial culture, sample preparation, instrument operation, spectra collection, spectra preprocessing, and mathematical data analysis. Without bacterial culture, a typical experiment generally takes <2 h.


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