The objective of the present study is to develop anaerobic co-digestion process which satisfies features required to achieve sustainable development by adjusting the component of feedstock and modelling of anaerobic digestion process. Three features were proposed for waste treatment that were processing capacity, energy production capacity and stability. There were analyzed from the viewpoints of the mass circulation, the biogas yield and the modelling of anaerobic digestion process respectively. The developed process fulfilled the processing capacity and the energy production capacity because the feedstock made from food waste and paper had high total solid content and optimal C/N ratio. The mathematical model of anaerobic digestion process was developed to describe the dynamic behavior of anaerobic digestion process. Applying the model and the estimated parameters to the experimental period, the model revealed the fermentation state and predicted biogas yield accurately.
Photosynthesis is a crucial process for the existence, development, and productivity of crops. Appropriate measurements should be met to evaluate and control the photosynthesis quality accurately. In this study, we presented advantages and compared the results from two measurement methods used on strawberry plants, namely, the single-leaf method (SL), and the whole-plant method (Wp). The leaf age of 12―15 days, optimal in the area and photosynthetic potential, were suitable to measure a representative leaf by the single-leaf method. The Wp showed the complete patterns and trends of whole-plant photosynthesis under different environmental conditions while this was a restriction in the SL. However, the light response curve patterns showed no differences regardless of measurement methods. The photosynthetic values between the two methods were only significant differences under low CO2 and PPFD. The limitations of SL were mainly from the manners and measurement conditions, which led to significant differences with the Wp. In conclusion, we believe that the whole-plant method may be the most suitable, nonetheless, the single-leaf method is still high valid if there are appropriate manners.
A mechanism of increasing the shoot fresh weight (SFW) of leaf lettuce under alternating red (R) and blue (B) irradiation by light-emitting diodes (LEDs) was investigated based on plant morphogenesis. Seedlings of leaf lettuce (Lactuca sativa L. var. crispa‘Greenwave’) were cultivated under seven alternating irradiations, i.e., R24B0, R20B4, R16B8, R12B12, R8B16, R4B20 and R0B24, in which RxBy implies x and y hours of irradiation for red and blue LEDs, respectively. The results of these treatments were compared to those of two simultaneous irradiations: one containing no dark periods and the other containing a 12-hour period, i.e., sR24B24 at a photosynthetic photon flux density (PPFD) of 100 μmol m-2 s-1, and sR12B12 at a PPFD of 200 μmol m-2 s-1. Multiple regression analysis was conducted to investigate the causal relationship between the plant morphological characteristics (PMs) and SFW. The increase in the number of leaves with the red-light period in alternating irradiation treatments increased the total leaf area and consequently the SFW. On the other hand, the difference between PMs in alternating and simultaneous irradiations depended on the individual leaf area (ILA), where ILA under alternating irradiation treatments was significantly larger compared to that under simultaneous irradiation treatments.
We performed an expression analysis of flavonoid-related genes such as chalcone synthase (CHS), chalcone isomerase (CHI), flavanone 3-hydroxylase (F3′H), flavonoid 3´-hydroxylase (F3′H), and flavonol synthase (FLS) in order to investigate the effects of light exposure on rutin biosynthesis and to determine the rutin content in green and white asparagus spears (Asparagus officinalis). Gene expression levels for the downstream enzymes in the biosynthesis pathway, i.e., F3′H and FLS, were significantly higher in green spears than in white spears; however, no significant difference was observed in the expression of upstream genes, such as CHS, CHI, and F3H. Furthermore, the expression of FLS was the lowest among all flavonoid-related genes, which indicates that it might play an important role in rutin regulation. Rutin remained undetected in white asparagus spears, while green asparagus had relatively high amounts present. The results of this study may explain the molecular basis of the relationship between light exposure and rutin biosynthesis in asparagus spears.
We examined the effects of LED light spectrum and alternate lighting on the proliferation of protocorm-like bodies (PLBs) and formation of shoot and root on explants of Cymbidium Sweet Waffle ‘Tarte’in order to find the optimal lighting condition for micropropagation of the orchid. We maintained the treatments at 25±1℃ for 24 hours light period. We found that proliferation of PLBs was increased most under monochromatic green LED light (peak wavelength: 517 nm) and alternate green LED light and red LED light (peak wavelength: 631 nm). We also found that shoot formation was increased most under monochromatic red LED light and alternate green LED light and red LED light. Root formation was increased most under blue LED light (peak wavelength: 460 nm). Based on these findings, we concluded that alternate green LED light and red LED light is the optimal lighting condition, because PLB proliferation and fresh weight increase are important for micropropagation of orchids.