China
Africa
Explore chapters and articles related to this topic
Single-Cell Protein Production
Published in Debabrata Das, Soumya Pandit, Industrial Biotechnology, 2021
The present chapter deals with the production and downstream processing of baker's yeast and Spirulina. A need for protein has always guided the production of SCP processes, and this continues to be a significant factor in the development of both old and modern processes. Yeast cells and Spirulina are the two most common SCPs produced industrially due to high demand. Baker's yeast is commonly used as a leavening agent in baking bread and bakery products. Baker's yeast is classified on the basis of its moisture contents. Dry yeast forms are good choices for longer-term storage, often lasting more than a year at room temperatures. Genetically stable high-fermenting power yeasts are used in industries which can prevent autolysis. Proper mixture of beet molasses and cane molasses(60:40) is the best nutrient for the development of yeast cells. Yeast extracts have been essential ingredients in savoury tastes as well as in fermentation media over the last few decades. The growth of the baker’s yeast market is directly linked to the growing trend in consumption of processed and fast foodstuffs, especially bakery products. In the years 2004–2005, the European and Asian regions produced 51 million tonnes of bakery products, priced at US$107 billion. As a result of the growing global trend, China is currently one of the most attractive markets for baker's yeast, as its demand continues to expand as the population grows and the demand for bakery products shifts.
Fungal Biodiversity of Foods and Feeds
Published in Hasnain Nangyal, Muhammad Saleem Khan, Environmental Pollution, Biodiversity, and Sustainable Development, 2020
Abdul Fatima Majeed, Ali Akbar
Yeasts are usually single-cell microorganisms. Yeasts can grow in the presence or absence of oxygen that are known for their beneficial fermentations. They habitually colonize foods which contain a high sugar or salt concentration. Fruits and juices that are with low pH are also spoiled by yeast, and some grow on the meat and cheese surfaces. Four main groups of yeast that causes food spoilage are: Zygosaccharomyces bear high sugar and high salt concentrations and they are normal food spoilage organisms such as jams, honey, dried fruit, and soy sauce. Generally, growth is slowly, forms flavors and bad odors and carbon dioxide which may causes swell and burst to food containers. Debaryomyces hansenii grow at high salt concentrations as 24%, accounted for their common isolation from salt which are used to preserve olives, meats, and cheese (Gorski et al., 2006).
Applications
Published in Raj P. Chhabra, CRC Handbook of Thermal Engineering Second Edition, 2017
Joshua D. Ramsey, Ken Bell, Ramesh K. Shah, Bengt Sundén, Zan Wu, Clement Kleinstreuer, Zelin Xu, D. Ian Wilson, Graham T. Polley, John A. Pearce, Kenneth R. Diller, Jonathan W. Valvano, David W. Yarbrough, Moncef Krarti, John Zhai, Jan Kośny, Christian K. Bach, Ian H. Bell, Craig R. Bradshaw, Eckhard A. Groll, Abhinav Krishna, Orkan Kurtulus, Margaret M. Mathison, Bryce Shaffer, Bin Yang, Xinye Zhang, Davide Ziviani, Robert F. Boehm, Anthony F. Mills, Santanu Bandyopadhyay, Shankar Narasimhan, Donald L. Fenton, Raj M. Manglik, Sameer Khandekar, Mario F. Trujillo, Rolf D. Reitz, Milind A. Jog, Prabhat Kumar, K.P. Sandeep, Sanjiv Sinha, Krishna Valavala, Jun Ma, Pradeep Lall, Harold R. Jacobs, Mangesh Chaudhari, Amit Agrawal, Robert J. Moffat, Tadhg O’Donovan, Jungho Kim, S.A. Sherif, Alan T. McDonald, Arturo Pacheco-Vega, Gerardo Diaz, Mihir Sen, K.T. Yang, Martine Rueff, Evelyne Mauret, Pawel Wawrzyniak, Ireneusz Zbicinski, Mariia Sobulska, P.S. Ghoshdastidar, Naveen Tiwari, Rajappa Tadepalli, Raj Ganesh S. Pala, Desh Bandhu Singh, G. N. Tiwari
Fungi are a group of eukaryotes that include yeasts and molds. Fungi are neither plants nor animals as they possess properties similar to plants (cell wall) as well as animals (absence of chlorophyll). Yeasts are unicellular fungi which derive their energy from organic compounds and do not require sunlight to grow. Yeasts are larger than bacteria, but smaller than molds. Yeasts reproduce asexually by budding in which a small bud forms on the parent cell and gradually enlarges into another yeast cell. Yeasts are either obligate aerobes or facultative anaerobes. They grow best in a neutral or a slightly acidic medium and are generally destroyed above a temperature of 50°C. Yeasts are used in the food industry for leavening of bread and production of alcohol. However, their ability to grow at low pH and water activity (aw) make them organisms of concern for spoilage in fruit products such as juices and jams (Tucker and Featherstone, 2011).
The level of aquatic yeast as a possible indicator of microbiological quality of urban recreational water reservoirs
Published in Urban Water Journal, 2023
Magdalena Dzikowiec, Katarzyna Góralska, Ewa Brzeziańska-Lasota
Bathing water quality monitoring includes performing physicochemical tests (nitrogen, oxygen, chorion, pH, temperature), microbiological tests (the total number of high-range and low-range mesophilic bacteria, sanitary indicators, presence of cyanobacteria), analysis of the level of eutrophication of the reservoir, toxicological tests (e.g. presence of microplastics), but still does not include mycological studies (EAA Report 2020). However, as confirmed by many other authors, fungi are abundant in the aquatic environment (Monapathi, Bezuidenhout, and Rhode 2020; Hu, Liu, and Cai 2013; Góralska, Błaszkowska, and Dzikowiec 2020; Medeiros et al. 2012). Aquatic filamentous fungi are a permanent component of the ecosystem, while numerous yeasts are often associated with water pollution. Most yeasts belong to the high-range mesophilic species associated with living organisms, and therefore they may be potential human pathogens. Their presence in the water of recreational reservoirs may be a public health concern, which unfortunately attracts too little attention of the authorities (Monapathi, Bezuidenhout, and Rhode 2020; EEA Reports 2020). Therefore, a mycological analysis, especially of yeast, shouldPN-EN be incorporated into standard water quality assessment procedures. Systematic monitoring of urban water reservoirs should be extended to analyze the presence of potentially pathogenic yeasts. The use of yeast as a sanitary indicator requires much more research but the data obtained so far are very promising.
Waste paper valorization for bioethanol production: Pretreatment and acid hydrolysis optimization
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Wahiba Tadmourt, Karim Khiari, Ahmed Boulal, Lyes Tarabet
During fermentation, the yeast consumes sugar to produce the energy that is needed for reproduction and excretes ethanol and carbon dioxide into the environment. The concentrations of sugars and ethanol in the medium change over time in a correlated manner (Gavach 2010). At the beginning of the fermentation reaction (0 to 12 h), sugar consumption is low as shown in Figure 10, it ranges between 60 and 67% (w/v). This behavior can be explained by the yeast mechanisms of regulation and adaptation to its environment in order to maintain its homeostasis (Hohmann 2002). After 24 h, total sugars consumption becomes faster, this evolution could be due to increased yeast growth rate (Leveau and Bouix 1988). After 48 h, sugar consumption slows again and the pH of the medium becomes equal to 2.85, which means the formation of acids. During this phase, the growth rate begins to decrease and it corresponds to the exhaustion of the culture medium due to the disappearance of one or more compounds necessary for growth and often to the accumulation of inhibitory products resulting from the yeast metabolism. After 60 h, total sugars consumption becomes very slow predicting the end of the alcoholic fermentation. The growth rate of the yeasts becomes zero and the reproduction is stopped; the metabolic activity of the yeasts continues but their biochemical structure changes (Leveau and Bouix 1988).
The importance and prevalence of allopolyploidy in Aotearoa New Zealand
Published in Journal of the Royal Society of New Zealand, 2020
Anna H. Behling, Lara D. Shepherd, Murray P. Cox
Introduced allopolyploid taxa of importance to the New Zealand economy are also prevalent well beyond the agricultural and horticultural sectors. Saccharomyces, the fungal genus of the model organism S. cerevisiae (brewer’s and baker’s yeast), is instrumental in brewery practices worldwide. Saccharomyces cerevisiae is the descendent of an ancient allopolyploidisation event, although genetic analyses have revealed extensive diploidisation, resulting in only minor retention of duplicated gene copies, most commonly those associated with beneficial novel properties (Wolfe 2001; Pfliegler et al. 2012; Marcet-Houben and Gabaldón 2015; Wolfe 2015). Notably, S. cerevisiae, an ale (top fermenting) yeast, is also a parent of the allopolyploid lager (bottom fermenting) yeast, S. pastorianus (Casaregola et al. 2001; Lodolo et al. 2008). However, it is the genomic contribution of its other parental species, S. eubayanus, that granted S. pastorianus the specific sugar and sulphite metabolism changes necessary for its lager-brewing domestication (Libkind et al. 2011).