China
Africa
Explore chapters and articles related to this topic
Components of Nutrition
Published in Christopher Cumo, Ancestral Diets and Nutrition, 2020
Humans and other animals must consume food for energy because, Chapter 3 emphasizes, they are heterotrophs, organism that cannot manufacture energy and nutrients, except for vitamin D in the presence of sunlight. Heterotrophs contrast with autotrophs—plants, algae, and photosynthetic bacteria—which use sunlight for energy. Heterotrophs use food to fuel the chemical reactions that sustain life. Absent food’s energy, cessation of these reactions causes death. The fact that life requires energy raises the issue of quantification: How much energy does the body need for maintenance, growth, and reproduction? This question is difficult to answer given that several factors influence requirements.
Organic Matter
Published in Michael J. Kennish, Ecology of Estuaries Physical and Chemical Aspects, 2019
Green plants, via photosynthesis, supply most of the organic carbon production of estuaries. Photosynthetic bacteria, although potentially important in polluted and eutrophic systems, account for only a minor portion of the total organic carbon produced. Sulfate-reducing bacteria are obligate anaerobes (growing only in environments devoid of oxygen) frequently encountered at the upper edge of the reduced zone of tidal mudflat sediments and in anaerobic water masses. Chemosynthetic bacteria appear to be intermediate between autotrophs and heterotrophs,64 responsible for what is termed “secondary primary production”. Heterotrophs participate directly in carbon cycling by ingesting organic matter, converting plant organic carbon into animal organic carbon, and respiring or excreting metabolites and ultimately releasing elements subsequent to death and microbial decay.292 Various pathways of carbon transformation exist; however, carbon fixed by autotrophs ultimately enters abiotic carbon pools through respiration (CO2), mortality and defecation (POC), and secretion and degradation (DOC).24
Acetylcholine as a Regulator of Differentiation and Development in Tomato
Published in Akula Ramakrishna, Victoria V. Roshchina, Neurotransmitters in Plants, 2018
The cholinergic components affect the motility of two photosynthetic bacteria, namely Rhodospirillum rubrum and Thiospirillum jenense (Sastry and Sadavongvivad, 1979). ACh and AChE are present in cellular slime molds Physarum polycephalum and Physarella oblonga influencing the protoplasmic streaming (Hoitink and Dijk, 1966). The gill plates of some fishes contain ACh, AChE, and ChAT (Sastry and Sadavongvivad, 1979). Antagonists of AChR act as inhibitors of ACh-caused cell movements in sea urchin (Lauder and Schambra, 1999). Cell movements occurring during gastrulation and postgastrulation stages are regulated by ACh (Gustafson and Toneby, 1970).
An overview on cyanobacterial blooms and toxins production: their occurrence and influencing factors
Published in Toxin Reviews, 2022
Isaac Yaw Massey, Muwaffak Al osman, Fei Yang
The ancient cyanobacteria organisms, noticeable in rocks dating from the first thousand million years of the earth’s history and belong to the kingdom monera (Prokaryota), division eubacteria and class cyanobacteria (Ressom et al.1994, Omidi et al.2018), are a type of photosynthetic bacteria that live in water surface. As cyanobacteria colonies occur in shallow water, they appear in the fossil record in sedimentary rocks deposited in shallow seas and lakes. Cyanobacteria colonies identified as stromatolites emerge in rocks as fossilized mushroom shapes and sheets. Falconer (2005) reported that the Gunflint chert was one of the best stromatolite formations known in Lake Erie. It is of interest cyanobacteria was shown to possess a single circular chromosome completely sequenced in several species, plasmids and small circular strands of DNA (Schwabe 1988, Kaneko et al.1996). Whitton and Potts (2000) found that the chlorophyll-a and pigment phycocyanin observed in cyanobacteria photosynthetic membranes were responsible for the characteristic blue-green color of the many species. Pigments such as carotenoids and phycoerythrin which give a strong red color to some species may also be present (Bryant 1994).
Biofilm diversity, structure and matrix seasonality in a full-scale cooling tower
Published in Biofouling, 2018
L. Di Gregorio, R. Congestri, V. Tandoi, T. R. Neu, S. Rossetti, F. Di Pippo
The biodiversity and structure of phototrophic biofilms in the cooling tower varied with season, which only partially reflected seasonal variation in the source water and appeared to be mostly related to environmental changes. The tower operating conditions such as pH, water hardness and the presence of biocides most likely selected microorganisms from the source communities that were able to survive under specific conditions. Those capable of adhering to the available surfaces in the cooling tower, eg members of the bacterial families Sphingomonadaceae and Comamonadaceae, may initiate biofilm formation. Subsequently, seasonal variations in irradiance and water temperature shaped the communities and accounted for differences in biofilm assemblages observed over the year. In particular, the effect of these factors may have initially driven the composition of the phototrophic fraction that was dominated by diatoms in winter, green algae in summer and cyanobacteria in the period at intermediate temperatures. Later, the diversity of non-photosynthetic bacteria developed, being mainly affected by the interactions between microorganisms. The analysis of biofilms grown in microcosms under light and temperature control in order to mimic the operational conditions of cooling towers may provide further insight into the combined effect of abiotic conditions and biotic interactions on the diversity and structure of biofilms in industrial systems. Deciphering seasonal changes in the composition and structure of biofilms is crucial to defining specific control treatments in order to efficiently counter the dynamic evolution of biofouling in cooling towers.
Collective excitations in α-helical protein structures interacting with the water environment
Published in Electromagnetic Biology and Medicine, 2020
Vasiliy N. Kadantsev, Alexey Goltsov
Experimental investigation of the coherent vibrational dynamics in proteins was intensified by the observation of long-lived coherent excitonic states in light-harvesting proteins in photosynthetic bacteria (Engel et al. 2007). The results of 2D IR coherent spectroscopy suggest that the coherent vibrations in photosynthetic pigment–protein complexes contribute to the effective electron and energy transport due to the electron-vibrational couplings (Chenu et al. 2013; Duan et al. 2017; Kolli et al. 2012; Rolczynski et al. 2018). It is notable that Fröhlich in 1968 proposed the role of coherent longitudinal electric modes (polarization waves) of low frequency (0.01–1 THz) in the storage of light energy in photosynthesis (Fröhlich 1968b).