def _summarize_kraken(fn):
    """get the value at species level"""
    kraken = {}
    list_sp, list_value = [], []
    with open(fn) as handle:
        for line in handle:
            cols = line.strip().split("\t")
            sp = cols[5].strip()
            if len(sp.split(" ")) > 1 and not sp.startswith("cellular"):
                list_sp.append(sp)
                list_value.append(cols[0])
    kraken = {"kraken_sp": list_sp, "kraken_value": list_value}
    return kraken
get the value at species level