The phytoplankton structure of Merin Lagoon: a Subtropical World Biosphere Reserve System (Brasil–Uruguay)

The phytoplankton composition and abundance in the large, subtropical coastal Merin Lagoon (Brazil-Uruguay) were analyzed seasonally between 1998 and 1999, based on plankton net and bottle samples in 38 stations. The lagoon is connected to the choked Patos Lagoon forming a complex ecosystem with a drainage basin of 201626 km2. Temperature and conductivity presented similar seasonal trends, with lower values (mean 15 °C and 70 µS cm–1, respectively) in austral winter (July–August 1998) and higher (mean 25 °C and 105 µS cm–1, respectively) in summer (January 1999).Atotal of one hundred and fifty three microalgae belonging to 8 classes were identified in the lagoon. Most species belong to the genera Staurastrum (8 species). and Scenedesmus (6 species). The species of genera such as Aulacoseira (Bacillariophyceae), Cryptomonas (Cryptophyceae), Monoraphidium (Chlorophyceae) and Planktolyngbya (Cyanobacteria) were present throughout the year. Diatoms predominated in spring and shared dominance with Cyanobacteria in summer and autumn. In winter, Chlorophyceae and Cryptophyceae dominated in the community. Phytoplankton spatial variability and abundance reached their maximum in March’98 (autumn) with 3600 ind mL–1, while in November (spring) relatively low abundances were found in the lagoon (average 1126 cells mL–1). The abundant phytoplankters were Planktolyngbya limnetica (943 cells mL–1), Aulacoseira (1874 cells mL–1), Staurosira construens (847 cells mL–1) and an unidentified unicellular volvocalean (1066 cells mL–1)

DETERIORAÇÃO DE REFRIGERANTES POR LEVEDURAS

Refrigerantes são bebidas não alcoólicas carbonatadas e constituem ótima fonte de glicídios. A composição química adocicada, o pH menor que 4,3, a aw maior que 0,90 e a atmosfera dos refrigerantes oferece condições favoráveis ao desenvolvimento de diversos microrganimos, incluindo leveduras deteriorantes..A deterioração ocasionada nos refrigerantes não constitui um risco à saúde das pessoas, mas este fenômeno prejudica a imagem de fábricas de refrigerantes, como também pode causar sérias perdas econômicas..Essas perdas podem ser minimizadas com o rastreamento da origem dos focos de contaminação, bem como conhecendo o risco potencial que cada levedura representa para o produto..As leveduras comumente detectadas em bebidas não alcoólicas carbonatadas, são as Brettanomyces sp, Candida lipolytica, Candida sp, Criptococcus albidus, Cryptococcus laurentii, Debaryomyces hansenii, Hanseniaspora sp, Hansenula sp, Kloeckera sp, Kluyveromyces sp, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Rhodotorula mucilaginosa, Rhodotorula glutinis, Rhodotorula rubra, Pichia sp, Saccharomyces cerevisae, Saccharomyces sp.,Saccharomycodes ludwigii, Schizosaccharomyces sp, e Zygosaccharomyces sp. SOFT DRINK DETERIORATION BY YEASTS Abstract Soft drinks are non alcoholic carbonated beverages that become an excellent source of glycids. Sugar composition, pH lower than 4.3, aw higher than 0.90 and atmosphere of soft drinks are conditions that contribute for the development of many microorganisms, including spoilage yeasts. Soft drink deterioration is not a health risk for people, but this phenomenon damages the beverage companies image and can yield serious economic damages. This problem could be reduced knowing the contamination focus origin, and also understanding the potential risk that each yeast represents to the product. The common yeasts found in nonalcoholic carbonated beverages are Brettanomyces sp, Candida lipolytica, Candida sp, Criptococcus albidus, Cryptococcus laurentii, Debaryomyces hansenii, Hanseniaspora sp, Hansenula sp, Kloeckera sp, Kluyveromyces sp, Zygosaccharomyces bailii, Zygosaccharomyces rouxii, Rhodotorula mucilaginosa, Rhodotorula glutinis, Rhodotorula rubra, Pichia sp, Saccharomyces cerevisae Saccharomyces sp, Saccharomycodes ludwigii, Schizosaccharomyces sp and Zygosaccharomyces sp

Seagrass and submerged aquatic vegetation (VAS) habitats off the Coast of Brazil: state of knowledge, conservation and main threats

Seagrass meadows are among the most threatened ecosystems on earth, raising concerns about the equilibrium of coastal ecosystems and the sustainability of local fisheries. The present review evaluated the current status of the research on seagrasses and submerged aquatic vegetation (SAV) habitats off the coast of Brazil in terms of plant responses to environmental conditions, changes in distribution and abundance, and the possible role of climate change and variability. Despite an increase in the number of studies, the communication of the results is still relatively limited and is mainly addressed to a national or regional public; thus, South American seagrasses are rarely included or cited in global reviews and models. The scarcity of large-scale and long-term studies allowing the detection of changes in the structure, abundance and composition of seagrass habitats and associated species still hinders the investigation of such communities with respect to the potential effects of climate change. Seagrass meadows and SAV occur all along the Brazilian coast, with species distribution and abundance being strongly influenced by regional oceanography, coastal water masses, river runoff and coastal geomorphology. Based on these geomorphological, hydrological and ecological features, we characterised the distribution of seagrass habitats and abundances within the major coastal compartments. The current conservation status of Brazilian seagrasses and SAV is critical. The unsustainable exploitation and occupation of coastal areas and the multifold anthropogenic footprints left during the last 100 years led to the loss and degradation of shoreline habitats potentially suitable for seagrass occupation. Knowledge of the prevailing patterns and processes governing seagrass structure and functioning along the Brazilian coast is necessary for the global discussion on climate change. Our review is a first and much-needed step toward a more integrated and inclusive approach to understanding the diversity of coastal plant formations along the Southwestern Atlantic coast as well as a regional alert the projected or predicted effects of global changes on the goods and services provided by regional seagrasses and SAV