Thursday, January 29, 2015
YOLO COUNTY NEWS
99 CENTS

Sequencing opens window on wine’s microbial terroir

By
From page A5 | December 05, 2013 |

It’s widely accepted that terroir — the unique blend of a vineyard’s soils, water and climate — sculpts the flavor and quality of wine.

Now, a new study led by UC Davis researchers offers evidence that grapes and the wines they produce are also the product of an unseen but fairly predictable microbial terroir, itself shaped by the climate and geography of the region, vineyard and even individual vine.

Results from DNA sequencing revealed that there are patterns in the fungal and bacterial communities that inhabit the surface of wine grapes, and these patterns are influenced by vineyard environmental conditions. The findings appear online this week in the Early Edition of the Proceedings of the National Academy of Sciences.

“The study results represent a real paradigm shift in our understanding of grape and wine production, as well as other food and agricultural systems in which microbial communities impact the qualities of the fresh or processed products,” said David Mills, a microbiologist in the department of viticulture and enology and department of food science and technology.

He noted that further studies are needed to determine whether these variations in the microbial communities that inhabit the surface of the grapes eventually produce detectable differences in the flavor, aroma and other chemically linked sensory properties of wines.

The study co-authors suggest that by gaining a better understanding of microbial terroir, growers and vintners may be able to better plan how to manage their vineyards and customize wine production to achieve optimal wine quality.

To examine the microbial terroir, the researchers collected 273 samples of grape “must,” — the pulpy mixture of juice, skins and seeds from freshly crushed, de-stemmed wine grapes.

The must samples were collected right after crushing and mixing from wineries throughout California’s wine-grape growing regions during two separate vintages. Each sample, containing grapes from a specific vineyard block, was immediately frozen for analysis.

The researchers used a DNA sequencing technique called short-amplicon sequencing to characterize the fungal and bacterial communities growing on the surface of the grapes and subsequently appearing in the grape must samples.

They found that the structure of the microbial communities varied widely across different grape growing regions. The data also indicated that there were significant regional patterns of both fungal and bacterial communities represented in Chardonnay must samples. However, the Cabernet Sauvignon samples exhibited strong regional patterns for fungal communities but only weak patterns for bacterial communities.

Further tests showed that the bacterial and fungal patterns followed a geographical axis running north-south and roughly parallel to the California coastline, suggesting that microbial patterns are influenced by environmental factors.

Taken together, these and other results from the study reveal patterns of regional distributions of the microbial communities across large geographical scales, the study co-authors reported.

They noted that it appears that growing regions can be distinguished based on the abundance of several key groups of fungi and bacteria, and that these regional features have obvious consequences for both grapevine management and wine quality.

Collaborating with Mills were graduate student Nicholas Bokulich of the viticulture and enology department, John Thorngate of Constellation Brands Inc., which supported the study through sample and metadata collection, and Paul Richardson, CEO of MicroTrek Inc., a company founded to provide microbial mapping services for vintners.

— UC Davis News

Comments

comments

  • Recent Posts

  • Enter your email address to subscribe to this newspaper and receive notifications of new articles by email.

  • .

    News

    Work continues to modernize Davis Healthcare Center

    By Lauren Keene | From Page: A1

     
    Holman continues to educate and inspire

    By Daniella Tutino | From Page: A1 | Gallery

     
    ‘Huck’ and ‘Tom’ float old Arboretum dock to removal

    By Special to The Enterprise | From Page: A1 | Gallery

     
    Teens arrested after midnight joyride

    By Lauren Keene | From Page: A2

     
    Biologists: Raising California dam would harm salmon

    By The Associated Press | From Page: A2 | Gallery

    Meet the mayor for coffee at Peet’s

    By Enterprise staff | From Page: A3

     
    Author joins radio show

    By Special to The Enterprise | From Page: A3

    Make your own SoulCollage on Sunday

    By Special to The Enterprise | From Page: A3

     
    Overweight video game avatars ‘play’ worse than fit ones

    By Special to The Enterprise | From Page: A3 | Gallery

     
    Walk through Quail Ridge Reserve on Feb. 14

    By Enterprise staff | From Page: A4

    Calling all chicken owners: Apply for coop crawl, share information

    By Special to The Enterprise | From Page: A4

     
    Hopmans named associate vice provost for global affairs

    By Special to The Enterprise | From Page: A5

     
    Review motivation to refresh your healthy-habits plan

    By Special to The Enterprise | From Page: A6 | Gallery

    Tips to protect skin this winter

    By Enterprise staff | From Page: A6

     
    For health and healthy appearance, there’s just one quick fix

    By Special to The Enterprise | From Page: A7

    Measles outbreak grows

    By Anne Ternus-Bellamy | From Page: A9

     
    NAMI-Yolo examines inpatient services at potluck

    By Enterprise staff | From Page: A9

    .

    Forum

    Basement living, with attitude to match

    By Creators Syndicate | From Page: B5

     
    50 years since Ash Hall

    By Special to The Enterprise | From Page: A10 | Gallery

    Can climate change bring us together?

    By Special to The Enterprise | From Page: A10

     
    Paso Fino coming to a vote

    By Letters to the Editor | From Page: A10

    .

    Sports

    Aggies still looking for record hoops win

    By Enterprise staff | From Page: B1

     
    Blue Devil Hammond has a huge day at home

    By Evan Ream | From Page: B1 | Gallery

    Pent up? Join Davis’ latest athletic event

    By Evan Ream | From Page: B1 | Gallery

     
    Two in a row for Devil boys

    By Enterprise staff | From Page: B1

    UCD roundup: Aggie football players crack the books

    By Enterprise staff | From Page: B2

     
    Youth roundup: Harper hoopsters off to hot start

    By Enterprise staff | From Page: B2 | Gallery

    Treys send Toronto past Kings

    By The Associated Press | From Page: B8

     
    .

    Features

    What’s happening

    By Anne Ternus-Bellamy | From Page: A8

     
    College Corner: Have wanderlust? Go overseas for college

    By Jennifer Borenstein | From Page: A8

    District learns from bomb threat incident

    By Kellen Browning | From Page: A8

     
    It’s Girl Scout Cookie time!

    By Anne Ternus-Bellamy | From Page: A8 | Gallery

    Feenstra-Fisher wedding

    By Special to The Enterprise | From Page: A9

     
    .

    Arts

    Show explores the evolution of dance

    By Enterprise staff | From Page: A11

     
    A rose by any other name — if there is one

    By Michael Lewis | From Page: A11

     
    Acclaimed guitarist Adrian Legg to play at The Palms on Saturday

    By Special to The Enterprise | From Page: A11 | Gallery

    .

    Business

    .

    Obituaries

    James George Tingus

    By Special to The Enterprise | From Page: A4

     
    .

    Comics

    Comics: Thursday, January 29, 2015

    By Creator | From Page: B6