The small‐subunit ribosomal RNA genes (SSU rDNA) from the four symbiotic dinoflagellates, Symbiodinium corculorum Trench isolated from the bivalve mollusc Corculum cardissa (from Belau, Western Caroline Is.), S. meandrinae Trench, from the scleractinian coral Meandrina meandrites (from famaica, W.I.), Gloeodinium viscum Banaszak et al. from the hydrocoral Millepora dichotoma (from the Gulf of Aqaba), and Amphidinium belauense Trench from the acoel flatworm Haplodiscus sp. (from Belau) have been amplified by the polymerase chain reaction, cloned, and sequenced. Following alignment of these complete sequences to homologous sequences from six other dinoflagellates, eight api‐complexans, six ciliates, six chromophytes and oomycetes, three ascomycetes, two rhodophytes, two chlorophytes, and two myxomycetes (with Physarum polycephalum as the outgroup), phylogenetic reconstruction was conducted using Fitch and Margoliash distance, DNA maximum likelihood, and Wagner parsimony methods, with bootstrap resampling. All methods generated trees with similar topologies. The inferred “across Kingdom” phylogeny reemphasizes previous reports that show that the dinoflagellates, the apicomplexans, and the ciliates share a common ancestry and that the dinoflagellates are distantly related to the chromophyte‐oömycete lineage. The evidence supports the concept of a polyphyletic origin of dinoflagellate‐invertebrate symbioses, as symbiotic dinoflagellates represent seven genera in at least four orders. The three symbiotic species, S. corculorum, S. meandrinae, and S. pilosum, consistent with their morphological and biochemical similarities, cluster most closely. Symbiodinium pulchrorum Trench, the symbiontfrom the Hawaiian sea anemone Aiptasia pulchella, is more distantly related to them. Gloeodinium viscum is not closely related to the Symbiodinium species. Amphidinium carterae (free‐living) and A. belauense (symbiotic) also appear to be distantly related to Symbiodinium. Some symbionts (e.g. S. corculorum, S. pilosum) from distant geographic locations (the Indo‐Pacific and Caribbean, respectively) were found to be very closely related, whereas S. pulchrorum and S. corculorum from the Pacific were found to be distantly related. Analyses of 10 additional symbiotic and nonsymbiotic dinoflagellates, using partial SSU rDNA sequences to generate a tentative dinoflagellate phylogeny, indicate that members of the genus Symbiodinium cluster with most of the other (free‐living) dinoflagellates in the genus Gymnodinium. The genus Amphidinium, as represented by A. carterae and A. belauense, appear to be distantly related to the other members of the Gymnodiniaceae. This analysis, combined with morphological and biochemical data, indicates that the symbionts S. pulchrorum (from Aiptasia pulchella) and S. bermudense Trench (from Aiptasia tagetes) from the Indo‐Pacific and Caribbean, respectively, are very closely related but are not identical.

Extruded bioplastic was prepared from cornstarch or poly(β-hydroxybutyrate-co-β-hydroxyvalerate) (PHBV) or blends of cornstarch and PHBV. The blended formulations contained 30 or 50% starch in the presence or absence of polyethylene oxide (PEO), which enhances adherence of starch granules to PHBV. Degradation of these formulations was monitored for 1 year at four stations in coastal water southwest of Puerto Rico. Two stations were within a mangrove stand. The other two were offshore; one of these stations was on a shallow shoulder of a reef, and the other was at a location in deeper water. Microbial enumeration at the four stations revealed considerable flux in the populations over the course of the year. However, in general, the overall population densities were 1 order of magnitude less at the deeper-water station than at the other stations. Starch degraders were 10- to 50-fold more prevalent than PHBV degraders at all of the stations. Accordingly, degradation of the bioplastic, as determined by weight loss and deterioration of tensile properties, correlated with the amount of starch present (100% starch >50% starch > 30% starch > 100% PHBV). Incorporation of PEO into blends slightly retarded the rate of degradation. The rate of loss of starch from the 100% starch samples was about 2%/day, while the rate of loss of PHBV from the 100% PHBV samples was about 0.1%/day. Biphasic weight loss was observed for the starch-PHBV blends at all of the stations. A predictive mathematical model for loss of individual polymers from a 30% starch–70% PHBV formulation was developed and experimentally validated. The model showed that PHBV degradation was delayed 50 days until more than 80% of the starch was consumed and predicted that starch and PHBV in the blend had half-lives of 19 and 158 days, respectively. Consistent with the relatively low microbial populations, bioplastic degradation at the deeper-water station exhibited an initial lag period, after which degradation rates comparable to the degradation rates at the other stations were observed. Presumably, significant biodegradation occurred only after colonization of the plastic, a parameter that was dependent on the resident microbial populations. Therefore, it can be reasonably inferred that extended degradation lags would occur in open ocean water where microbes are sparse.

The Caribbean tunicate, Ecteinascidia turbinata produces the anti-cancer agent ET-743 that could well be a metabolite of an associated bacterial strain. This current study aims at the analysis of bacteria that are persistently and specifically associated with this invertebrate. Utilizing techniques such as denaturing gradient gel electrophoresis, DNA sequencing and phylogenetic analysis of bacteria from E. turbinata collected from different locations in the Caribbean Sea, we report here the identification of five possible persistently associated bacteria. Of these, only one organism, Candidatus Endoecteinascidia frumentensis, was found specifically associated to E. turbinata from the Caribbean and has also been found to be associated with E. turbinata from the Mediterranean. These experiments suggest that assessment of bacterial diversity associated with invertebrates from different geographical sites might be an effective way of identifying persistently and specifically associated bacteria.

Sexual stimulation increases the Q-carotene content of the fungus Phycomyces blakesleeanus. The same effect is observed in single cultures exposed to natural and synthetic trisporates and in intersexual heterokaryons. Synthetic racemic (9Z)-methyl trisporate B, a trisporate precursor made by cultures of the (+) mating type, stimulates carotenogenesis only in ( -) cultures. Synthetic racemic (9Z)-methyl trisporate C is less effective and the corresponding all-( E ) isomers and other related compounds are inactive. Sexual stimulation of carotenogenesis is additive with the stimulations induced by light, retinol, dimethyl phthalate, and mutation of the gene cars.