Russula griseopurpurata

Why in News?

A mushroom collected beneath a sal tree in Meghalaya’s Ri Bhoi district in 2022 has been identified as a species new to science.

• Scientific Name - Russula griseopurpurata.
• The species name refers to its greyish-purple colour.
• Genus - The mushroom belongs to the large and diverse Russula genus.
• The researchers said the Russula genus comprises about 2,000 species worldwide, with more than 180 species documented in different parts of India.
• The species has so far been recorded from Meghalaya and West Bengal.
• Elevation - It was found at an elevation of 320 metres.
• Supporting Tree - It was found growing beneath Shorea robusta, commonly known as sal.
• Appearance - The mushroom has a greyish-purple cap that develops cracks as it matures.
• Its gills show characteristic forkings near the stalk.

• Researchers examined these and other microscopic features before using its DNA sequencing and phylogenetic analysis to establish its identity.
• The study examined 3 specimens of the new species two from West Bengal and one from Meghalaya.
• The Meghalaya specimen, deposited under the number GUBH 20331, generated an ITS sequence recorded as PQ432811 and was included in the phylogenetic analysis.
• The three specimens grouped together with strong statistical support, supporting their identification as the same species.
• The mushrooms were found singly or in scattered groups beneath sal trees.
• Although some Russula species are edible, the researchers have not established R. griseopurpurata as edible.
• Its reported mild taste and odour do not constitute a food-safety assessment.

Reference

Hub Network | Mushroom found in Meghalaya’s Ri Bhoi

Traditional Diets and Indian Tribes

Why in News?

Researchers have found that traditional diets, particularly those rich in dairy and grains in trans-Himalayan populations, were associated with distinct gut bacteria and locally adapted microbial strains.

• The study stressed the need for India-specific microbiome research and probiotics.
• Led by - Researchers from BRIC-National Centre for Cell Science (NCCS), Pune, and Stanford University, USA.
• It concentrated on 8 Indian tribal communities.
• It showed that what people eat over generations may leave a lasting imprint not just on their health but also on the trillions of microbes living inside their gut.
• The study analysed healthy adults from the Warli, Gond, Madia, Kabui, Boto, Balti, Brokpa and Purigpa communities across 4 geographically diverse regions of India.
• Researchers examined stool samples alongside dietary habits of participants using advanced DNA sequencing.
• The 4 trans-Himalayan groups regularly consumed milk, homemade butter, wheat and barley, as also rice, turmeric and chilli.
• The research showed that the communities had more diverse gut microbiomes and significantly higher levels of Bifidobacterium compared to people who didn’t widely consume the aforementioned food.

Bifidobacterium – It is a group of bacteria known to break down carbohydrates and commonly used in probiotic products.

• Researchers also found that gut microbes in the trans-Himalayan participants carried distinct and diverse genes involved in digesting lactose, galactose and grain-derived carbohydrates, suggesting that the microbial communities had adapted to foods these populations consumed traditionally.
• It noted that other than food, geography, altitude and lifestyle may also influence gut microbes.
• Moreover, the most striking finding was that strains of Bifidobacterium adolescentis isolated from these participants were genetically distinct from many strains commonly found in industrialised countries.
• Although belonging to the same bacterial species, the Indian bacterial strains carried unique combinations of carbohydrate-processing genes, indicating adaptation to local diets.
• An important question raised by the findings was whether probiotics developed in Western countries were equally effective for Indian populations.
• Researchers cautioned against assuming that all probiotic strains behaved similarly simply because they belonged to the same bacterial species.
• Consumers should not assume that all members of a probiotic species are interchangeable.
• Rather than rejecting imported probiotics, the study highlighted the need to evaluate them in Indian populations and develop indigenous probiotic strains based on healthy Indian microbiomes.

Reference

Times of India | Tribal community diets