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Marine micro-organisms have been proven to be a major source of marine natural products (MNPs) in recent years, in which filamentous fungi are a vital source of bioactive natural products for their large metagenomes and more complex genetic backgrounds. This review highlights the 390 new MNPs from marine-derivedPenicilliumfungi during 1991 to 2014. These new MNPs are categorized based on the environment sources of the fungal hosts and their bioactivities are summarized. [ABSTRACT FROM AUTHOR]

In order to assess the putative toxigenic risk associated with the presence of fungal strains in shellfish-farming areas, Penicillium strains were isolated from bivalve molluscs and from the surrounding environment, and the influence of the sample origin on the cytotoxicity of the extracts was evaluated. Extracts obtained from shellfish-derived Penicillia exhibited higher cytotoxicity than the others. Ten of these strains were grown on various media including a medium based on mussel extract ( Mytilus edulis), mussel flesh-based medium ( MES), to study the influence of the mussel flesh on the production of cytotoxic compounds. The MES host-derived medium was created substituting the yeast extract of YES medium by an aqueous extract of mussel tissues, with other constituent identical to YES medium. When shellfish-derived strains of fungi were grown on MES medium, extracts were found to be more cytotoxic than on the YES medium for some of the strains. HPLC- UV/ DAD- MS/ MS dereplication of extracts from Penicillium marinum and P. restrictum strains grown on MES medium showed the enhancement of the production of some cytotoxic compounds. The mycotoxin patulin was detected in some P. antarcticum extracts, and its presence seemed to be related to their cytotoxicity. Thus, the enhancement of the toxicity of extracts obtained from shellfish-derived Penicillium strains grown on a host-derived medium, and the production of metabolites such as patulin suggests that a survey of mycotoxins in edible shellfish should be considered. Significance and Impact of the Study Penicillium strains isolated from bivalve molluscs produce extracts exhibiting a higher cytotoxicity than extracts from Penicillium strains isolated from the surrounding marine environment. The use of a mussel-based medium for cultures of some shellfish-derived strains enhances the cytotoxicity of extracts when compared with classical media. The production of cytotoxic compounds and of the mycotoxin patulin on such a host-derived medium highlights a potential health risk for shellfish consumers. [ABSTRACT FROM AUTHOR]

The harmful dinoflagellate Prorocentrum minimum reportedly has variable toxicity to grazing animals. We used the bay scallop Argopecten irradians irradians as a bioassay organism to compare expression of harmful effects of P. minimum cultures in growth or senescent phases. The non-toxic alga Rhodomonas sp. was used as a control. Exposure to both types of P. minimum cultures decreased the degree of shell opening, amount of biodeposits produced, motility and byssal-thread attachment. As P. minimum cultures approached senescence, effects became more severe, and mortality increased to 15% in scallops exposed to senescent P. minimum. Pathological effects of P. minimum on scallops included derangements of scallop digestive tubules and the adductor muscles, and abnormal hemocyte distributions, which were more severe in scallops exposed to senescent cultures. These findings help to explain the variable toxicity of P. minimum to scallops and other bivalves reported in the literature. Further, these findings demonstrate that the definition of a 'harmful algal bloom' should probably be expanded to include physiological status along with identity and abundance of a phytoplankton species. [ABSTRACT FROM AUTHOR]

Prorocentrum minimum (Dinophyceae), a planktonic microalga forming red tides, is considered a potentially toxic species. In view of its likely harmful role, accurate identification of P. minimum to species and/or subspecies may be particularly important. Like most thecate dinoflagellates, species identification is largely based on morphology of the theca and on features of both flagellar and auxiliary apical pores. In this study, we compared 18S rDNA gene sequences to confirm that P. minimum strains isolated from the Baltic (3 strains) and Adriatic (3 strains) Seas were the same species, and compared the morphology of the apical pore region among the strains. Our results confirm that the platelet arrangement in the apical pore region is a stable morphological character, independent of the strain origin and culture growth phase. In addition a small tooth, opposite to the apical collar in the auxiliary pore area, is proposed as an additional diagnostic character. [ABSTRACT FROM AUTHOR]

We review the occurrence of fungal endophytes in marine organisms, in particular of seaweeds and mangrove plants, and compare them to obligate or marine-derived fungi. The ability of endophytes to produce a wide range of new or novel bioactive compounds is also discussed. [ABSTRACT FROM AUTHOR]

Prorocentrum minimum (Dinophyceae) is a red tide­forming toxin­producing planktonic microalga from coastal waters worldwide. In this study, the morphology of natural and cultured populations of P. minimum was examined to investigate whether the species can be split morphologically into more species. The diacritical features of cell shape and size, ornamentation of thecal plates, and architecture of the apical pore area and intercalary band were studied from scanning and light micrographs. Cell size of P. minimum is similar in Baltic Sea samples and a culture from the Chesapeake Bay, USA. Cell shape varies from triangular to oval­round including intermediate forms in valve view. The thecal surface is covered by evenly distributed short spines, while the circular thecal pores are mainly situated near the valve margin. The intercalary band is rim-like, striated and covered with short evenly distributed spines. The architecture of the apical pore area is ornate and more complex than previously pointed out. It is V­shaped, located on the right valve in a shallow depression and accommodates a large elongated flagellar pore, and a small round auxiliary pore. Four distinct apical features are present: next to the auxiliary pore there is a curved collar, and adjacent to the flagellar pore arise a forked double tooth, a short single tooth, and a ridged edge near the left valve margin. Our study suggests that the ornamentation of the apical pore area of P.minimum is independent of cell shape or growth place,and it is considered a stable morphological character of this cosmopolitan morphospecies. [ABSTRACT FROM AUTHOR]