Efficacy of Rhodotorula glutinis and Spirulina platensis carotenoids in immunopotentiation of mice infected with Candida albicans SC5314 and Pseudomonas aeruginosa 35.

Enhancement of the immune response leading to protection against bacterial and fungal infections was shown using different schedules of immunization with microbial pigments and a polysaccharide. The group of mice given carotenoids of Rhodotorula glutinis (preparation I) and polysaccharide of Spitulina platensis (IV) survived for 2 weeks after Pseudomonas aeruginosa infection. The groups of mice given carotenoids (I), polysaccharide (IV), I+IV and with the crude phycocyanin of S. platensis (III)+IV survived for 2 weeks after Candida albicans infection. All other groups recorded a maximum level of mortality reaching 2 mice per group either after immunization or post-infection. Adding the carotenoids, phycocyanin and polysaccharides to food as additives might therefore enhance the human immune response against microbial infections.

Effect of crude seaweed extracts on seed germination, seedling growth and some metabolic processes of Vicia faba L.

Crude extracts from three green seaweeds (Cladophora dalmatica, Enteromorpha intestinalis, Ulva lactuca) and the three red algae (Corallina mediterranea, Jania rubens, Pterocladia pinnate) were prepared. Their effects on germination, growth of seedlings, chlorophyll content and other metabolic activities of Vicia faba were investigated. The crude extract of C. dalmatica showed maximal activity, and it increased seed germination, length of main root and shoot systems and the number of lateral roots. All the crude extracts of seaweed increased protein content in both root and shoot systems, total soluble sugars and chlorophyll content in leaves. The cytokinin content of the green algae was higher than that in red algae. Growth of seedlings of V. faba was stimulated but to different degrees.

Stable chloroplast transformation in Chlamydomonas reinhardtii using microprojectile bombardment.

The chloroplasts of Chlamydomonas reinhardtii were transformed using a vector (paadAGUS4.1) that contained a spectinomycin-resistance gene (aadA) as a selectable gene, and bacterial uidA (GUS) as a reporter gene, and pea 4.1 kb D-loop containing sequence. The vector was introduced into the alga through particle gun bombardment. The transformed colonies were screened for the presence of foreign genes by Southern hybridization using GUS, aadA and 4.1 pea Ori probes. Expression of aadA and GUS genes was detected in all colonies that were grown on spectinomycin. A detailed restriction analysis followed by southern hybridization of total genomic DNA using pea 4.1 kb D-loop as probe indicated that the D-loop sequence can serve in site-specific integration of foreign DNA due to high homology. Restriction analysis of different colonies showed that the foreign DNA was probably present in a mixture population of autonomous segment and integrated in the native chloroplast genome.

Abolishing cadmium toxicity in Chlorella vulgaris by ascorbic acid, calcium, glucose and reduced glutathione.

Addition of ascorbic acid, calcium (Ca2+), glucose and reduced glutathione (GSH) to the cadmium (Cd2+)-amended Kuhl medium significantly accelerated the growth and chlorophyll content of Chlorella vulgaris. This enhancement was found to be dose dependent. Their relative effectiveness against Cd2+ on growth and chlorophyll content has been arranged as GSH > Ca2+ > glucose > ascorbic acid. However, Ca2+ offered more protection against Cd2+ toxicity on protein contents, followed by ascorbic acid, GSH and glucose. The different concentrations of all amelioratives completely alleviated the toxicity of Cd2+ on total carbohydrates to exceed the control level. Photosynthetic oxygen evolution showed more response to Ca2+ and glucose in alleviating Cd2+ toxicity. On the other hand, at certain concentrations, GSH, Ca2+, ascorbic acid and glucose stimulated respiratory oxygen uptake over the control level. The uptake of Cd2+ dropped significantly in cultures supplemented with 20 microM ascorbic acid, glucose and GSH, while Ca2+ (30 microM) significantly lowered the Cd2+ uptake by 58% indicating that Ca2+ had a more antagonistic effect against Cd2+.

Effect of atrazine herbicide on growth, photosynthesis, protein synthesis, and fatty acid composition in the unicellular green alga Chlorella kessleri.

Sublethal atrazine concentrations induced a general inhibition on growth, photosynthesis, and dark respiration in the green alga Chlorella kessleri. 14C-protein hydrolysate indicated a maximum incorporation level by 5 microM atrazine after 48 hr. Progressive reduction in protein synthesis was associated with increasing herbicide concentration at all experimental periods. The herbicide had preferential effect on the associated fatty acid composition of total and phospholipids. After 24 and 48 hr the herbicide stimulated fatty acids synthesis at concentrations where photosynthesis was inhibited. Meanwhile, stearic and miristic acids disappeared at 15 microM after 24 hr and the total polyunsaturated fatty acids were not affected after 48 hr. Fatty acid synthesis was sensitive to treatment at 72 hr by 5 and 10 microM atrazine, whereas the total saturated fatty acids were completely inhibited.